I can turn my neck that far and not break it. The key is to not jerk your head, but to move it slowly. Of course, I might just be more flexable than other people.
Also, if you take the angle of the body into account, her head is nearly aligned with her shoulder, and the chin is barely behind it at all, making it a reasonable place for the face to be facing.
Critique of critique aside, this was well-animated, well-voiced, and and amusing. As for the chair-jump, silly, but unlikely to be attainable, especially when you consider that the chair had wheels. Even if she pulled off the rapid-repositioning of her legs, the chair would have tipped over.
Realism aside, I enjoyed it.