@ACommonTreasuryForAll good luck with finding a solution that works for you and them.
It's only now in my mid 30s I've started to find my sleep cycle has become earlier. I think one of the reasons for my late cycle is because the evening is the quiet time I have for me, when there aren't any demands on me or my time and I've noticed others who are ND say similar (the bed ready feeling).
A few years ago I adopted an evening routine of reducing the light I'm exposed to, 40w bulbs in lamps, warm light only, gradually reducing screen brightness on all & any devices as the evening goes on and utilising the blue light filter on my phone from 10pm (I can set it to automatically come on). Reading a book instead of social media and TV later in the evening helps prime me for sleep too.
Now I find if watch any TV past 11pm my sleep is really disrupted!
The old truism of exposing myself to daylight and fresh air in the morning helps too, even if its just opening blinds and windows.
My family know I'm grumpy, even a bit combative if I'm woken too early, and give me space first thing and thankfully don't take it personally!
You could also look at sleep tracking watches which identify the best time in a sleep cycle to wake up - might appeal to their ASD.