Suggest Treatment For Sleep Disorder In A Teenager

My 17 year old daughter has been going days at a time without sleep for over 1 year now (non anxiety & non depression - but for over 5 years she has been battling severe chronic illness w/ multilple symptoms that keep evolving). Are there any reaonably safe sleep medications to try? Most meds don't help her sleep but leave her feeling unable to move in a zombie-like state. She also has extreme chronic pain (constant) for which we haven't been able to find relief.