The eyes are commonly the toughest part and i think you're doing amazing job here. But, i have to say that her forehead is kinda,, unnatural because it's too smooth and bright compared to other parts of her skin. Too sharp for me.. Still, it's a great pic, i like it.
This is incredible! Seriously, it is fantastic. The only negative thing i have to say about it is the hair in the bottom right corner could fall a bit more natually, but overall this piece is amazing. Keep up the good work.