Wow, Mike, that is amazing!

My only suggestion is to add a subtle expression on her face. At the moment, her face is very neutral and doesn't really convey any sort of personality or attitude. It's also very symmetrical and plain. Even a tiny little raise of an eyebrow or a small curl on the corner of the lips will add a lot of personality and depth to her. That will move her from being a pretty model to a full blown character.