Have you talked to her doctor about the insomnia?
My son has long had problems with anxiety and insomnia. We did work out a system where I would stay with him (I am a single mom), and snuggle and hold his hand while I slept. Even if he couldn't sleep it would help him stay calm. He had a box of soothing items he could fidget with that wouldn't disturb my sleep, and he was allowed to read.
He went to school sleepless at times, and it was difficult. I was much the same way as a child.
I don't have any really helpful advice to give about the insomnia. Probably the only real wiy to deal with it is through the doctor and through counseling and possibly a psychiatrist.