Watch the outline of the jaw into the neck, its wierd. if you cant resolve the angle with shadow, make her hair fall over it.
Shading- On her shady side: the face contour is great - you sense the structure. The dark side of the nose is heavy handed. It would not be so regularly dark around the end of the nose. I think I need another nostril indicated. (The silliness of these sentences is entertaining me) The lighter side of the face is confusing. I would make a dark contour line between lips. maybe add soft shading to upper lip, that little curve, and under mouth -What would receed a bit. Maybe even match the nose end shadows to what would also be indicated at the chin to be consistent with light source. This lighter side of the nose is strange. Maybe shadow just near the eye and towards the bottom where it comes forward. And the cheek shadow, I dont think you need it at all.