Oh, wow. I love your style in this: the way you've successfully done her skin tone and the shading is especially good! (That's something that I find unreasonably difficult orz)
Her face, as well - it's like you infused a realistic picture of her with just a little cartoon character. I've gotta say that the effect works wonders, here. Somehow it just seems to express her personality perfectly.
One final thing: kudos to you, for not using hard edges and linearts. That's something I have yet to even hope to be able to do!