I mean no disrespect to the model on the right, but I think that whole right half is unnecessary. You have three focal points: the tree, the girl on the left, and the girl on the right. The girl on the right isn't particularly interestingly posed anyways.
I would crop to just before the tree begins on the right, and maybe shave off a few pixels on the left. This would create a much more simpler and stronger image, IMHO.
If you choose to do this, maybe make another crop for the model on the right as well so you don't upset her.