It's a physics based power, so it can be hard to follow.

Okay so basically the way it works is:
Each vector is like muscles. She has to sort of learn how to affect each different vector the way someone would learn a new muscle. The way I was going to have her explain it to the group is: "Imagine if you woke up with a tail tomorrow. It would be really hard for you to figure out how to move the muscles in it because you didn't have that infant stage where it became natural for you. Or like moving a single toe at a time. It's difficult to figure out how to do." The only ones she knows how to use with any real skill are the ones she needs to move, and even them she's got limited control over.
A vector is basically anything with both magnitude and direction. So stuff like force, velocity, acceleration, gravity, dislocation, etc. Dislocation is the odd one out there because it's the one not as many people know about. It's basically the difference between two locations. Movement requires force to actually get it to start moving and continue moving, because movement is a force and generates further force. Velocity is basically speed. Acceleration is just change in velocity. So movement requires all three of these, and because she can't generate any vectors above zero since she's in her own field, she has to control these three vectors to move. And since her own weight vector is zero, if she doesn't either control it directly or wear weights that escape her field to give her weight, she'll basically just fly into space.
How the field itself works is a bit mathy, but it basically cuts all vectors of anything that enters it by an additional five percent each inch closer to her it gets, meaning that something that goes all the way through to make contact with her would have all its vectors cut by a total of 75%. So if something is moving at 100 mph, it would only hit her at 25 mph. Her biggest problem is that anything that stops within her field would continuously have its dislocation cut by the correct percentage until eventually the thing in her field was stuck to her with a dislocation of zero. The longer something is in her field, the more it gets cut by the correct percentage based on how close to her it is. This also means that things basically just slow down when they get close to her, so to take the snake example, she'd have plenty of time to move out of the way of a biting snake because it would get slowed down so much.
The cost is basically that controlling one to three vectors drops her blood sugar by ten points an hour, and extending her field drops her blood pressure. And since she needs to control vectors just to move... She's basically got to eat a lot of sugar constantly or she'll eventually go into diabetic shock. And in extreme situations, where she'd have to extend her field, there's a huge risk of her passing out or worse due to low blood pressure. And while she's passed out, she can't affect her weight, so if she isn't wearing weights to keep her on the ground, she'll just start floating away. The lucky thing is that while she's passed out, she's not moving with her controlled vectors so her blood sugar isn't dropping too.

As I said above, Violet is best described by her actions and by what has been said about her. As such, I've collected several statements from her family and previous classmates. Having been home-schooled well beyond her age's general education, she skipped all of primary school as well as middle school and spent only a single semester in each year of high school. During her sophomore "year", at age twelve and thirteen, her fellow students wrote quotes and stories about her to be collected into a book that she was given when she completed the "year," as a farewell present for her moving schools. The following are several excerpts. Somehow, a common theme traveled among the student body, and many chose to use this theme in their statements.
"'Violet is simultaneously the most childish and most mature teenager I've ever met.' I had math class with her, and it was insane. So you know those assignments we get every day or two? Well, most of us had to take at least half the class to finish them, but I swear to god she did them in like thirty seconds. I'd be on the fourth problem and she'd have already given hers to the teacher to be graded. But that's not the weird thing. For the rest of class, she'd be on her phone and she was playing a Hello Kitty game. Not like, a game just with the characters, but like a game specifically made for little kids. I asked her the name once and looked it up and it was for three years and up, and just a serious Hello Kitty game. She played it three times, just in a row over the first month or so, and then she moved on to this game where you have to move blocks so that one will be able to get to a certain place. There were days where I'd watch her for the entire class, and she would literally just do the same level over and over for the whole hour."
I thought it would be funny for a highschooler to play a Hello Kitty game for kids in class, so I just sorta did it. Same with doing the same puzzle over and over for the whole class. It just seemed like it would be funny to do so I did it.
"Violet is terrifying sometimes. One day, a kid fell down the stairs and got really hurt, he was bleeding and his ankle was twisted weird, I think he landed on a pen or something to cause the bleeding? Me and Violet both saw him fall and rushed over to see if he was okay, and as he was crying she just suddenly turned her head and stared at the top of the stairs for a long time. It felt like ten minutes as I was trying to get her attention again. She was staring really intently like there was something dangerous up there. Then all the sudden she just turns really quickly so she's looking at me and said 'I think I just saw a ghost.' Then she turned to the injured kid and grabbed him, holding his cheeks in her hands and his eyes open with her thumbs, and just stared into his eyes for a second before saying 'I think it was yours if you don't get to a fucking hospital soon.' with a totally serious expression as if she'd just told him he had an hour to live. Then she just stood back up and walked down the stairs to the first floor and went somewhere. The kid practically went into shock, I wound up accidentally bumping his injured leg into a door frame and he just sort of whimpered instead of shouting in pain. I confronted her the next day about it and she just said it was 'a joke to help him calm down.' Ever since then, I've been terrified of getting seriously hurt when nobody but her is around to help, because I think she'd just ignore me."
Oh, I remember that. Yeah, that was pretty hilarious. I actually had to leave school because I was laughing so hard after walking away. But yeah, I'd totally have left this girl if she got hurt, probably after making a joke, heh.
"Violet is insane as hell but I love it. I've pretty much been stalking her whenever I could in school after something in shop class. Remember the buzzsaw there? Not the portable one, but the one on a lever that lowers it to just barely not touching the surface you set the wood you're working with on? One day in class, she was over there using it, and all the sudden there was this loud crash as the saw went back up into place since the lever was suddenly let go while it was down. Everyone in class was startled and looked over at her. She just turned around and looked at the teacher with a totally straight face and asked 'Can I use the bathroom now?' and the teacher asked 'Well, can you hold it until after class?' And she just held up her left pointer finger which was covered in blood and had bone showing through this huge cut for a few seconds, then grabbed it with her other hand and said 'Sure' and just turned around and went back to working on her project while holding her finger with her right hand. She didn't even flinch or scream or act like she was in pain at all, it was creepy. Well the teacher sent her to the nurse and I assume she went to the hospital. I'm sure you all remember the day she got on the intercom somehow? That was the day after. Remember how just all the sudden she was talking on it and said 'If any students need help with learning shop safety, I'm holding a special study group on the roof after school. Bring a knife and food.' and how shop class for everyone was just tool safety for the next week or so while they cleaned the saw? Ever since then I was trying to see her as often as I could because I wanted to see how she'd react to stuff."
Oooooh, that's right. That was actually really funny, I wound up laughing the entire time I was getting my finger patched up. I was lucky I noticed it just before it cut through the bone or I might have lost the finger.
"So I know the whole thing is supposed to be 'Oh she's the most and least mature person I've ever met.' but this story is much more important. To set the scene, I was waiting in the office where the assistant principals are because I was accused of having pot on me. Really, I had just spent the night at a friend's place and his big bro had been smoking and drinking all night so we both smelled like it, but that's why I was there. All the sudden Violet walks in and sits down a seat away from me playing with a screwdriver, like tossing it back and forth in her hands or flipping it and catching it. Well, Maxwell opened his door after a minute and called her in, but neither of them remembered to shut the door, so I could hear them talking. He said that there had been several reports of her having a weapon on her, and she just looks at him and says 'Anything could be a weapon.' I could tell that me and him both thought the same thing, which was 'oh shit, the screwdriver.' But she just slams it down on his table and picks up the little statue he had on his desk, then slams it into her forehead hard enough that the entire office heard it, then she just stands up, says 'But yes, I always carry a pocketknife in case I'm in danger in or out of school.' and walks away with all this blood coming from her forehead. I watched through the glass behind me as she just walked out of the school. Well, she didn't show up for a week after that, and when she did I asked her why she had been gone and she told me it was 'a self applied suspension, to save Maxwell the trouble of kicking her out for a week.' Then she goes to the office and I follow her and pretend to wait for something as I sat down because I wanted to see what happened. She walked into Maxwell's office and pulled out this knife with one of those giant erasers shoved on the blade and said 'I childproofed the knife.' with a totally serious voice and walked out, presumably to her first class. I lost it at that."
See, this kid gets it. My jokes are awesome.
"Violet is simultaneously the most and least mature person I know, and she also might be slightly demonic? Okay so I had biology with her, and when we were dissecting actual frogs she just put these medical gloves on and did the dissection in about a quarter of the time it took everyone else. But then the day we were doing a virtual dissection of snakes, she set the room on fire and nobody knows how she did it. It was like a magic trick or something but nobody saw her use a match or a lighter or even like sticks or something, and when she was searched afterwords supposedly they didn't find anything. But it was like cartoon physics. The teacher brought in a dead snake to dissect while we all did the virtual ones, so she could show us what they actually looked like, and I swear Violet's stare and anger is what started the fire. She was glaring at the teacher as if she had killed her family and then all the sudden the paper in front of her caught fire. It was small enough that we didn't have to leave the school but class got cancelled. There's a rumor that the occult club considers her a paranormal being because of that day, even."
Right, that. I was pissed. We were told for weeks that it was just a virtual dissection and we wouldn't have to actually cut open snakes, and then the fucking teacher brought one in anyway! I mean, I know the snake was raised to be dissected but that's fucked up! Everyone responsible for that shit should be tied up and sent to biology classes to be dissected when learning the human body, and they should be dissected while they're still alive. But about the fire. I had sandpaper because I was working on my shop class project outside of class, and I had it in my hand because I liked playing with it. Then when I saw the dead snake I got really pissed and I think I just wound up rubbing the sandpaper against itself so hard and fast that a bit of it came off while really hot and landed on the paper. It would be really cool if I could light fires with my eyes though.
"Well, one of the scariest things my daughter ever did was when she was seven or so. We were at the beach and she suddenly came over with a snake she was holding just behind the head, and said 'Look dad! It's a pelagic sea snake!' Later that day, I looked up what that is and found out it was incredibly venomous, but at the time all I knew was that my little girl was holding a snake that she herself was telling me had a really potent venom. I was panicking on the inside and she asked me if we could keep it. She asked 'Dad, can we keep...' then she turned it so she was looking under it and stared at it for a few seconds before continuing 'her!? I'm sure Nagi would love a new friend! Not that I'd let her near my Nagi, she might bite him, so she'd need her own tank. Plus she needs water and Nagi doesn't so she'd need her own anyway...' I was terrified that she was going to get bitten but I had to convince her not to try to bring it with her, so I told her that the snake probably preferred to live out at the beach instead of cramped in a tank. She just looked at me like I said something confusing and asked 'Why? I'm sure she'd prefer a life where she just eats and lays about. I'd love a life of just eating and laying about. Then again, it might get pretty boring... And she might have a husband and kids...' And this is why that day was burned into my memory, because she turned the snake and held it about an inch from her face and stared into its eyes for what felt like forever with how panicked I was, and she asked it 'Why are you so important, dangit?' and walked off with it to put it back where she found it. I followed to make sure she didn't get bit but she gently threw it into a little pool that formed from the ocean water and walked away as if there wasn't a dangerous snake right behind her. Luckily the snake just slithered away in the other direction but it was probably the most frightening moment of my life."
It's not like I was in any danger anyway. I knew how to correctly handle snakes since I was five. It was the first thing I actually tried to learn on my own, cause snakes are cool.