Sorry, this is all nonsense, and you and DH are handling it badly.
She’s an adult. She’s got a job. It puts her sleep and leisure hours a bit out of whack.
On the food thing, I’ll give you a gold star if you can convince an 18yo to turn up to family dinner when she’s got something better to do. (Like sleep!)
I know this is harsh, OP, but your DH is being a controlling dickhead about “family days out”. Your adult daughter is under no obligation to participate - unless you’ve imposed a rule that she can only live at home if she participates. And I really, really hope you haven’t done that, because it would be really stupid.
If you are really poor and can’t afford school uniforms for your younger children, then it’s ok to ask her to contribute a little from her wages. Otherwise, a young adult who is between school and uni stays at home - and is fed - free of charge.
Do you really have no insight into how this looks from the outside? At best, this is your eldest child (and it’s always hardest with your eldest as you have no experience to guide you), so you’re making a bit of a hash of things and getting a bit uptight, sometimes a bit nasty, because your child is becoming an adult and you’re confused.
At worst, you’re guilty of some downright controlling behaviours which are quite inappropriate for an adult of 18, and you risk serious and possibly permanent damage to your relationship with your child.