She was between semesters at school, we had 3 kids, 2 of them potty trained, 1 of them in preschool. She had been receiving help with college from others in the family, so she looked at this as an opportunity to give back. She didn't ask for anything, but we still gave her $50/day, paid for her flight, and left a bunch of her favorite foods when we left. I think I got a steal, but she was happy, so we were too.

Clearly that might not work for you, but if you have family like that, it might be a reasonable option.