My daughter’s sleep

I have a six year old daughter who gets up very early, anywhere between 4.00am and 5.15am every day. My partner and I, have since birth followed every single rule and routine in order to help our children get the best possible night’s sleep. I have read dozens of guides to best practices with little benefit. 

The issue I have is 99% of available advice applies only to the neurotypical child, neurodivergent and you’re on your own.

Our daughter is on the spectrum awaiting diagnosis, she takes a medicine for her epilepsy and melatonin to help her sleep.
She sleeps in our bedroom, she’s extremely clingy and demands attention every waking moment of the day, it’s truly exhausting.

Can anyone offer me any tips/advice for my particular predicament as the thought of getting up at 4.30am for the next ten years or so has limited appeal. 

Rob