[@Wraithblade6]
Wow, wall of text.

She has two ways of fighting with hemokinesis. The first way is to control her own blood. She can form her blood into 'blades', but they'll be significantly weaker and less sharp than a metal blade. Able to cut flesh, but not bone or armour. They'd have a hard time getting through a proper leather coat (real leather, not the fake stuff). However, she can extend her blood beyond her body infinitely, as long as a string of it is connected to her body. Meaning that her 'range' depends on how much blood she uses, and the more blood she uses to form blades or weapons, the weaker she becomes physically. Using too much would incapacitate or kill her.

The second way is by controlling the blood of others. In order to do this, she has to pretty much touch them. She can only control blood within 5cm of her, so if she were to touch someone's chest she would be unable to, for example, control the blood in their brain. She would, however, be able to burst the blood vessels in their lungs, for example. For a human, her touch is pretty much lethal. They'll instantly start suffering from internal bleeding, and die in a matter of minutes. Vampires, however, don't need pesky things like internal organs (on the whole). As such this technique is far less useful against vampires, although blood loss can weaken them or slow them down. This is one of the reasons she prefers to fight humans.

Also, the 'strength' of the blood, or the amount of force she is able to apply to an object from range using her blood, is a bit higher than her physical strength. The amount of force could push over a car, but not lift it for any significant amount of time. Slightly stronger than your average run-of-the-mill vampire, but not exceedingly strong.

The amount of blood she is able to control at once is variable. Hypothetically she can control any amount of blood, as long as it fits within her 5cm radius. Which is not a lot of blood, honestly speaking. More dangerous, however, is the amount of blood that counts as 'her' blood. When she drinks blood she effectively converts it into 'her' blood, allowing her to control it even outside of her 5cm radius, as long as there is a string of it that leads to her body. As such, the limit for the amount of blood that counts as 'her' blood is the amount of blood that she's able to contain within her body (about 2.75 liters). She's able to contain 'her' blood outside of her body as semi-permanent blood constructs in order to bypass this limit, but blood kept this way will soon harden, and thus become inanimate. Also, the digestion process for blood takes approximately a minute, meaning she can't instantly use any blood she drinks. There must also be enough room in her body to accomodate for the new blood in order for her to drink blood, for obvious reasons. 

Vampires are inherently resistant to the application of her powers, so I'm not sure why you would need to make them resistant to the effect of them as well. Her main method of killing (internal bleeding and organ damage) is practically useless against most lineages of vampires, and significantly reduced in effectiveness against regenerating werewolves. 

And yes, she does need to enter the 5cm radius to control the blood of strangers, still. And she can only 'digest' the blood through her claws (although she can also control it into her claws).