A couple of thoughts: First of all, I agree with Kristal's comments. While it might not be noticable to the untrained eye, the background treatment really stands out. I'm also not fond of the close crop; I wish that the RH side was pushed out a little more and that her legs, at least in part, were visible in the image. While I like the idea of the pose, I'm not sure that it was executed in the best manner; I can't seem to access the EXIF data for this image, but it looks like you used a fairly short focal-length lens which has resulted in her head looking a little too big for her body.
All that aside, it's by no means a bad shot.
Just my $00.02 worth - your mileage may vary.
~John