This from a Mum with 2 girls who manage their own finances, and a son who at 33 has never really been financially independent, and has a drink problem.
It's not that he never has his own money, but the minute he has it it's spent, and then he needs medication, food or hasn't quite enough for his rent.
We are not well off, I'm disabled, my husband gets his state pension but we manage. But like you, every week I'm subbing my son, he says it's a loan, but he has NEVER paid anything back. Gradually over the years everyone else has stopped the loans so it's just us now, and we have had to stop now as well. Food costs seem to have gone up so we really do have nothing else left.
Shockingly he hasn't been evicted, he hasn't wasted away, in fact he's cooking at home......pubs are shut, he's not even buying take a ways. It seems like what my daughter's and other family members are saying.....he will survive when he has to, but why bother when he doesn't have to?
I suspect your daughter is the same, at the moment she doesn't have to manage, so she doesn't. Tell her that prices are up for you too and you can't afford to help her. Tell her to contact Step Change, they will help her sort out any debts that she may have and to sort out a budget with her that she can actually afford.
If you can afford to put a little money to one side for the children specifically, maybe you could help with school uniform, trips or a winter coat? But make sure it's you who buys them not you giving money to your daughter. She may say she has to buy it through the school, but if you want you can contact the school and ask for access to their uniform order form, or to pay for a trip etc.
She will manage, maybe with difficulty to begin with but I promise you she won't end up on the streets. Just keep telling her you can't help, that she must contact stepchange, they will help her.