YAB a bit unreasonable - why does she have to play with her siblings! No child (or young adult) is obligated to play with their siblings...
Your DH is totally out of order and seems not to understand the difference between 18 and 8. Of course she doesn't have to go on family outings and you can and should go without her.
Working 8 hour shifts finishing at 12 midnight you can't expect her to be in the same schedule as people working 9am to 5pm, it wouldn't work.
Most adults have a few hours between getting home from work and going to bed. If she finishes work at midnight when does she get in? 12:30? 1am? It's reasonable to chill out until 3 or 4am before going to sleep in that case.
It's unhealthy to radically vary sleep pattern by several hours regularly, so she does right to stay on her work pattern really. Some people have to swap between lates, nights and earlies but it's quite bad for your heart.
A compromise could be reached but she isn't even home on work evenings so eating together is only going to be possible when she isn't working, she's surely going to want to eat after work on those days.
Perhaps ask her to be up for 3pm every day so you can see a bit of one another and eat your evening meal together on non work days. That's fair as she's living at home.
Also if course she should tidy up after herself and ask about what she can and can't cook, put things on the shopping list and do a top up shop once a week or so, so your family meal planning isn't thrown by missing ingredients.