i think her head is twisted too far, making her collarbone jut out. she looks uncomfortable and something about her mouth open like that makes me want to see teeth. i think it's too dark in her mouth. she has beautiful skin.
Lovely, only thing for me: as much as her hair is a nice detail it also makes her eye look a bit weird. Some millimeters to the right and it would have ben wondderful.
nice (lighting, pose, model etc.) My issue if I may is with the hair in front of her right eye. Once I noticed it, I couldn't stop but being bugged by it. As I was trying to understand why (I'm not against portraits where you hide one eye in the shadow or under hair), I think the problem here is that I see the outer half of the eye. I would have prefered to have her eye fully hiden, while here the half visible part is dragging my attention.