Vipershark jinxed it.

[Chris2Balls [:B]]

I don't think the background suits your girl: she's seen from a slight angle, but the ground is flat. The tree is dark, maybe too dark, very straight and with small roots. I don't think you should use Dex's picture as a reference for your tree (but I'm not saying his isn't good, just not in the right context). Be boring and try and look at as many trees as you can, closely.
The girl's dress is strange, highlights are supposed to go on the folds, her legs seem to meet up in one point underneath the skirt (rather than following her hips), arms bit too short. But I might be destroying your style by saying some of that :s
Anyway, carry on the good work!