Gorgeous! I love the model, truly beautiful. The palette is striking with its contrast. The pose is perfect; it gives her a pensive look, like she is making up her mind, and makes her look seductive at the same time. This is one of my all time favorite portraits.
As for the model, I think you should do more with her. I love her look. Classic beauty is all I can say. If Alexandros of Antioch would have seen her, the Venus de Milo would have had that face.