this is a tall girl, with long legs, and unfortunately, this pose does little to accentuate that fact. something with her legs pushed outwards a little more might have given their length a better perspective. pulled back like they are, (and one kinda shadowed) i get the impression that her legs are shorter than they are, and her arms look longer by comparison. overall, it gives her a bit of a "lanky" look. I also think she should be turned a little more to her left, pulling her right arm out from behind her.
I love her expression and her "off in the distance" or "totally indifferent" look.
the lighting is wonderful, and it is framed up nicely.
im no pro though...and you know what they say..
those that can, do...the rest critique.