Yes, that is acceptable to me, but just barely. It was the very limits of what I am prepared to do. Anyway, she will be a human rogue with a fox amulet that allows her to transform. While she is in fox form, she will be, for all intents and purposes, the same as if I had her as a fox-person. Normally, I wouldn't do that, but if that is what it takes, so be it. I'm not the stubborn one, so I will compromise on this point.
Anyway, Grace, who you have just forced me to turn into a woman, is the daughter of a sorceress, who happens to be 100% human as well. When her mother died, she was left with only a few trinkets as inheritance. She was cared for by her alcoholic uncle until she was 18, when she was left out on her own. She became a dancer at a tavern, and supplemented her income by thievery. When Grace was 21, she tried on the fox amulet and turned into the orange-furred, bipedal fox that I think of her in my mind and that she is in every other RP I will ever use her in, without exception. She is somewhat smaller and weaker as a fox, but she is faster and has far better senses, along with better climbing abilities. She can switch between forms simply by touching the little wooden amulet, which is fox-shaped.
Although I am prepared to accept the compromise I have myself suggested, I should point out that since you have allowed my character for all practical purposes, it would do no harm to just let me take her all the way.
EDIT: So if magical entities exist, why can't we play as them? They're still in the game universe no matter if they are PCs or not.