Proportions and such
The overall sketch is pretty realistic and crap, but there are some proportional issues here and there. Her left arm is much thinner than her right and her waist and butt are too wide when compared to everything else. The legs seem a bit thin, too, but that might be an illusion from the butt's width. The value all around is good, but there are till some lines too visible here and there and they and some edges look a bit rough. The hair doesn't look realistic, but I suppose the focus of this was the body, so that's excused.
Rough, but you got the main thing and show potential. Keep at it.