Have to say that this is a lovely image just because of how lovely her eyes are and that smile!!! well she is going to be a real heart breaker one day. As for the composition? I would say I would like to see a little less of the dress and it's just too bright and takes the focus of her lovely face. If I were lucky enough to take a shot like this I would crop it from just under where her hair reaches below her shoulders and make play around with the shadows and lighting a little.
This is a lovely image and with a little work it would be an outstanding portrait.
Thanks for sharing it.