I think that this piece could use a little more tender loving care. You need to zoom in closely on the piece and erase the bits of background that you have left behind. Try using an eraser with a softer edge, such as a 60-70% hardness. When finished, taking the blur tool at something around a 5% strength around all of her rough edges will help better blend her into the background.
My eyes would love to see the designs and more, be coming from her, rather than at her, since she is in a "freedom" type stance. Also, I feel the glow that surrounds her, would be better off shooting off in a direction, rather than highlighting her. Although I feel that you did a great job with her hair and the movement it has, the very front, by her forehead could be better done to look more natural.
Furthermore, she isn't standing on anything and there is no depth to the background. Don't be afraid to push your character into another angle. Some polishing and touching up would do this piece wonders <img src="e.deviantart.net/emoticons/s/s…" width="15" height="15" alt="" title=" (Smile)" />