i like what you did here
aside from the proportions, I like this piece pretty much :).
Some critique I hope helps:
1) her left arm is...err it doesn't really make sense to me. from the elbow onwards it's a little hard to tell the anatomy, but perhaps its just the overall proportioning you did, leading to my 2nd point...
2) overall proportions are a little stumpy? she's wider in some areas (thighs) but slim as hell in other areas (arms). And she seems a little short and dwarfy.
Unless that's your art style, then okay. or if she's a kid I suppose.
Little girls with those abs scare the heck out of me though.