Hmmm.... I think her shoulder's aren't wide enough (you might know the old drawing trick that your chest/shoulder area are 3 heads wide and that the arm span is one's height). Her head is only 2 1/2 wide. Her body looks natural (awesome job!). And I like how the tree roots in the background climb down the wall and the subtle brick pattern is great too. The perspective looks fine and will influence how you color it. Overall, I think it looks great.
One thing that I notice right off is that the lines of the girl are lighter than the rest, which instantly draws my eye away from the girl. This isn't to much of a problem if you're going to color it though.