My parents do. They benefited from free university, cheap housing, final benefit pensions; their outgoings are smaller, they have free bus passes and winter fuel allowance, an enormous income and no work. Their children all work FT, have bigger outgoings (childcare, mortgages) and smaller or the same income. They can afford to take us, they want to take us, and they want us all together as an extended family – this has been the case as late teens, 20s on low incomes, 30s on reasonable incomes but setting up home/buying first homes and having £0 spare, 40s and established but all £0 goes on childcare.
I asked my dad about it and he pointed out that we (the adult children) could not afford our share of a holiday home that he could fund without batting an eye. So he could either fund it and have a lovely week with his children and grandchildren, or not fund it and not have that week, or know that his children would then struggle financially or tighten belts elsewhere to make the week happen.
However now we have better incomes, we do usually pay our own travel (though we holiday in the UK so this is trains or petrol), and contribute a food shop, or buy a meal or two out (for 8 adults and 7 kids, so not pennies!), or take it in turns to cover his and his partner’s share of ticket entries to an attraction.
When we were in your daughter’s position my parents would have absolutely paid for the holiday and transport and food, though not extras – so yes a meal out, but it’s not like the adult kids could have then gone to the pub on their dime if they were heading home, IYSWIM, and none of us took the piss, no ordering steak and 10 cocktails, not that that’s our family’s style anyway. And we’re always self catering and always all pitch in – my parents might have paid but we would make the meals, clean and tidy, research walks to go on, make the tea and run the baths when back from a muddy walk, and so on.
Just recently we’ve all had a bit more money (kids starting school so childcare bills going down), and we’ve been able to contribute more, take parents out for dinner, for a weekend, invite them on our own holidays without them needing to fund a thing. Your daughter isn’t in that position but one day she will be, and wouldn’t you want her to have family holidays and helping each other out as a habit by then? Rather than her going off and asking you to cat sit.