Starting melatonin

We have been on every pathway to getting more sleep for Miss A over the past year....
She delays getting to sleep and wakes usually twice a night. After asking her therapists for help they spent 6 months of trialing everything they knew. At the end the only thing we have stuck with is a weighted blanket and I'm not sure how well its working.
So we saw the sleep specialist and we have started with the first 2 recommendations- melatonin and vitamins.
Melatonin occurs in the body naturally and helps see signals telling the body to sleep.
From Wikipedia:
The melatonin signal forms part of the system that regulates the sleep-wake cycle by chemically causing drowsiness and lowering the body temperature...

It wasn't an easy decision to start melatonin for Miss A and in fact I started researching it months ago. Her occupational therapist suggested it but I wanted to know why I should do it. So the OT gave me some medical articles to read on how it works and what research has been done.
When we saw the sleep specialist I didn't ask about melatonin she suggested it as step one. Anne was great about explaining why it would work and how she decided on it. Miss A is taking a fast release melatonin which is designed to get her to sleep. It isn't a sedative and will not keep her asleep. The idea is she will get the message that going to bed means going to sleep. So 30 minutes before bed she has it in a liquid form and calls it her medicine. We have been going for a week and so far I haven't seen big changes but more small signals. She doesn't get in and out of bed as much. She still tries to play up and not go to sleep but less than before.
Our follow up with Anne the specialist isn't until February so I won't know until then how the sleep study went. In the meantime we keep going with melatonin and strict bedtime schedules.