The way the resort was set up, parents have unlimited amount of day-time to leave their children in the creche service. If you want to go out to dinner, you can also drop your children off in the same creche (and probably with the same sitters) as during the day, and they're open until 11:30 pm. Or if you'd rather have sitting in your own apartment, people who work in the creche will come in and babysit until 1:30 am. So it wouldn't have been strangers who were looking after Madeleine and the twins.