I like the lighting generally, nice contrast....the exposure looks good as does the composition. The pose looks a little forced and the 'bum' looks like a little spotlight is on it so I imagine you dodged that area.....nice but it looks a little too obvious. A small fill light at the back would work much better. Overall a very nice effort though.
I'm really diggin' the front lighting on this one and the warmth you have given. Something about me wants just a bit more (reflected) lighting on the back side to reduce the harsh shadow. I also think the focus is a little soft, perhaps a smaller aperture (?), but that could be what your aim was.