Alright here's my quick nitpicking session. It's crude so don't look to take it exactly as is, but it's to give an idea of things that might need work.
Assuming the light is coming from the top left, there are a few inconsistent light/shadow patterns, notably on the raised thigh and the side-boob (which needs a shadow!).
The crotch is a bit anatomically incorrect, so I brought it more in-line with your reference image. I added a face - it's based off reference which you might not like, and it's just a suggestion, but I would definitely rework it and concentrate the details there. After all, it's where our eye naturally drifts to when viewing a piece - character's faces!