Ooo...pretty.
Umm..okay, anatomical errors...there aren't many here. :] Mainly, the shoulders look sharp, when they should be round, and the nose is a bit long. That's it.
Err...colors! : D
Let's see. I think you colored the background, hair, and shirt wonderfully. I like that coloring style. However, the skin doesn't seem to be colored the right way. It seems like it's just the background colors...
Light should fall on the edges, like on the cheeks or edges of the bones. Your light seems to fall anywhere...please correct me if I'm wrong, and I don't see what you were trying to do. Also, you can make the shadows more defined.
Overall, a really good job. As I said earlier, I love how you colored the background, hair, and clothes. I even like the way you colored the skin; it gives her a soft, glowing look. It just doesn't seem to make sense.