The blue looks too happy, but that may actually work. Right now, I'd say work on her feet... they are kind of monstrous and her arms seem... I can't decide if that's muscle or flab. Her figure also could use a bit of work. it looks like she is fat or wind is blowing up there.
I suppose girls like pink better than blue, even if they are evil. And since the image is symmetric, it seems to work better centered on the shirt rather than off to the side.
