I really like the languid way she's floating here... her expression is so far away. I think this is an excellent design, but you are right: the anatomy does need a little work. The face is fine--you've got the animeish style down quite well. Her neck is a little skinny, though, even for anime, and I think it should be a little bit further to our right. The collar bones usually point out to the end of where the shoulders start--trace along yours, and I think you'll see what I mean (even though I'm incoherent, sorry...) so the line of them and the shoulders should be a bit more connected. The arms are also a little too thin, and the chest starts a bit too high. You have the right idea for the legs and hips, though, they are just slightly off center. And wow, those hands are GREAT.

So I hope that that's helped you a little... Keep up the good work!