I hope you don't mind, I did a drawover 'cause i'm not very good at words D:

So this is following the arm. I started with the arm, then tried to set up everything else to suit that. Her head isn't wide enough, but more difficult to me was the angle at which her face is turned- nearly pure profile. With the body twisted away from us and the head twisting towards us, it creates an unnatural pose. Possible, but kind of awkward.

This one I started with her head. If the body is more in profile, there's less conflict between the movement of the body and the movement of the head. If that makes sense. It means the shoulder needs to be pushed back significantly, but it improves the pose, I think.
I'm not terrific at anatomy so there are likely some bumps, but maybe that'll help smooth out some of the things that seem off? Very cool coloring, by the way.
fake ps- I didn't set the hips very well for balance on either drawover since the cloak covers it up and the pic doesn't seem to need the legs. If you do need the legs though, you'd probably wanna set the hips more centered under the head to improve the look of sturdiness or balance.