Very nicely done. The composition is great, not directly centered so an A+ in my book. Your colors are very subtle and fitting to the mood of the image. The trees and shallow focus create a nice frame around your subject and her black dress melts nicely into the frame.
Her skin might have a tad, just a tad bit too much yellow in it, but that is of course subjective. There are a few snow flakes I would remove, the one on the skirt of her dress (the soft blurred ones don't bother me but there is that one sharp one that catches the eye) and the big white fuzzy blur by her head (on the left).