Okay I need some help, advice, something!? We've noticed that Riley has been getting a bald spot on…

Okay I need some help, advice, something!? We've noticed that Riley has been getting a bald spot on the back of her head but we just thought she's loosing her baby hair, it happened with me. But last night I realized she is actually rubbing her hair off. When she's laying in her bed she will move her head back and fourth, side to side, shedding her hair. Something I can do to prevent that?