First one works, and the last one might be better if she turned her head a little towards the camera. Having her nose break the plane of her cheek doesn't help the shot. The other two don't work for me.

Good backgrounds, but the books on the right in the last shot are a little distracting.

Technically, they look like good conversions, but maybe bump the contrast up just a little bit (couple points is all). I don't see a real solid black, at least on the not-so-great monitor I'm at.