This is really good. I'm really liking your style! The shading is awesome and the fact that she isn't looking at you adds to the effect of this. It's amazing!
I'm also in love with the background. I like how you've merged images of lots of people and it makes you think more about the image and what's going on. The shading is awesome as well. You've chosen colours that really go well together and the lighting of the piece adds to the effect as well! I can't really fault this. It's just awesome!
I wish I could pick up a pencil and draw something like this!