the heads on last page are looking great (:
With this drawing, here are just somethings I notice. You seem to be unhappy with it, so I don't know if you notice this too, but whatever, I'll point it all out:
1. Her neck indicates that her head would be at a 3/4th view, however her head is facing towards us. It isn't aligned and looks kind of weird.
2. The arm reaching up is too short. Measure it and then place it against her side. If she relaxed her arm, basically it would only reach her hip, which is obviously not right
4. I was contemplating whether or not stating this since the style is anime, and anime typically doesn't have much shading, but I think it's fine to say. I think you should use darker values, especially on the face, which is hidden behind her hair and the fact that theres a bright light source she's forming out of her raised hand. That would create some intense lighting, I believe. This is just kind of a quick example I found of what I mean. Basically it would just create more depth in the image.
Otherwise, I think you did an overall cool job. From what I can tell, you didn't seem to mess up the angle of the right arm. If I'm wrong though, anyone feel free to say so :P