My DD is 12. in the last 6 months or so she has been having trouble both getting to sleep and staying asleep. She's always been a sleepyhead - early to bed and late up where possible - but now she just can't seem to get to sleep, and often wakes two or three times in the night for up to an hour at a go.
At first I thought it was exam stress, and it did seem to settle over the summer holidays. But now she's back at school and it's back with a vengeance. She woke at 3 yesterday and couldn't get back to sleep.
Are you sure she's not worried about anything at school? With friends? It must be making her very groggy, poor her. Are you able to try some relaxation and breathing exercises with her that she can do before bedtime to help her get off to sleep? What's her bed time routine like, do you allow her to take a book/tablet/phone to bed?