Talk with her doctor. If it is disruptive enough she may need a tiny bit of medicine to help her. I used to have trouble spending the night over places when I was younger. Now that I have had panic attacks as an adult, I realize I was having panic attacks when I was around 7 years old. I wish I had known then!
I hope she gets relief soon. Maybe play a favorite movie or show? When I had trouble falling asleep in late elementary school, Mom and I used watch the Santa Clause to help me fall asleep. Thinking of her!
Try advise from healthunlocked.com and see if they can offer advise