Well, I think she needs to blend a bit more with the background. Also, I am not sure if you used a render or if you rendered it yourself, but her hair is very blocky. You should always use a feathered selection when rendering someone's hair, that way it looks natural and doesn't pick up any pieces of the original background. The sig needs a bit more flow. Otherwise, the background is pretty cool and modern. Over all, nice work, just needs some adjustments.
Better. Now just duplicate the render layer once or twice to bring the main body of hair back in a bit more, and its great.