First, under bad traits, i'd reduce the multiple references to her mental instability. One is enough and gives others the point. it does sound like she's more animalistic than she is human. you might consider making a clear reference early on, in those lists. it doesn 't sound like she likes people at all. is she solitary, except for her pack? how does she get along within her pack? she sounds like she might be a bit of a seperatist even within her pack.
in her description, you talk about her nails being points. are those her fingernails when she is more human? or are those her claws when she is transfigured? I would think her claws would naturally be sharp.
it doesn't sound like there is much she is outwardly afraid of, except for losing her lycanthropy. i'd like to see you explore that. i presume that potionsmakers who understand lycanthropy and are always researching and working on improved wolfsbane potions, etc., might be threatening for her? anyone else? any particular wizards or wizarding families? or factions? i'd like to see her have a few more vulnerabilities.
I'm not sure the reference to the wolfsbane potion being a godsend to her is realistic, honestly. I'm not sure it really follows canon. My understanding about wolfsbane is that it prevents transfiguration. Are you sure that is a true-to-canon assessment of how that potion works? I was under the impression that Fenrir worked less about potions and dependence on chemicals and such as he was about self determination and controlling oneself to the point where it controlled the beast within to a given point. If you disagree, please say so.
The other thing that concerns me is that she has so many murders under her belt at a young age. We rarely accept characters who are so advanced in their skills, and we look for characters who have developed their skills in an age appropriate manner. Would you look that over, please, and perhaps bring that a bit more in line with her age? I don't mind that she's violent and animalistic. But, she appears to be a bit overpowered.
Lets see if some of those edits don't fix it. And speak up if I'm misreading!