I can see 2 things: first, she has what's needed. Second, (as you already said, maybe she was nervous) her approach to the camera is a cold water shower. Not a smile and whe she smiles looks like a gesture, not an angry look, she just looks between bored and "once the photog turns I'll steal his wallet" look. So, maybe I'd try taking some pics of her working on that look, no need to be nude. If you can't take something decent out of her even if she's dressed (hence taking away the "nervous" part), then try to find another girl. Otherwise, if it's just a question of her used to the camera and gaining confidence, you have some really good material. Just my
