She reminds me of my sister, who used to work in pubs so was home about 2am.
She was a gamer and loved the online games. She had 'friends' from all the way around the world on the games, which wasn't helpful as she'd purposefully stay up really late/early until it was their time to play in their time zone. Then she'd sleep until 4 or 5pm. But then, my Mum has never kept her sleep pattern well, so she would sleep til that time too.
My DD is 17. I would probably be accused of being a bit of a control freak, but I'd be telling your DD that I appreciated she didn't want to sleep the second she came in from her shift, but that I'd expect her up for 1pm ish, which would give her 8 hours sleep even if she didn't go to bed til 5.
Partly because her hours sound ridiculous, but mostly because it's going to be very difficult for her to quickly adapt her sleep patterns when university comes around.
My own DD would stay up til ridiculous o clock in the morning if allowed to. But DH is up early for work and she's not quiet when moving around her room and wouldn't dream of coming downstairs to be out of the way of us all. So she is asked to switch off any tech at 10ish (9 on school night) and then expected to chill, even if not actually sleep. That way there's half a chance she will be able to get up early enough for school the next day without being knackered.
I think It's not out of the question to expect all who live in the same home, adult or not, to stick to sociable hours and to be mindful of others.