Look - she is not really starting her adult life. She is swapping one set of parents for another set of parents. She probably hopes that the other set of parents have laxer house rules - let her find out for herself whether this indeed is the case.

You are not required to provide anything for her at this juncture. I would find out from her when she intends to get her own phone and cancel the family phone plan that you have been providing for her from that date on.

The other parents' house must be furnished, so the issue of bedroom furniture is not going to come up.

Let the other parents deal with some of it.