Something about the proportions isn't quite right. I think her head is too small, possibly? It's weird because of her cape, but there's just definitely something that isn't quite as it should be. Really lovely image, though - that is meant to be constructive feedback!
awsome composition man, i like how you have kept the detail at the top half of the body to draw the eye. love the contrast between light and darkl in this piece also. wish i could paint like this, keep it up man.