You're going to have to bite the bullet and learn how to study anatomy, my friend. The arm is clipping through her back and there's a lot of proportion and anatomy errors here. I reccomend checking out Proko on youtube, he has a good starter series on those fundamentals.
In addition to that, try to draw skeletal bits from photo references as much as possible, ESPECIALLY the skull. simply gaining a better understanding of the underlying structure to these bits and pieces will be like a giant steroid shot right into your art hole.