That's one of the questions you don't ask a kid, as it implies that they have a choice in the matter, which they do not. It's not fair to the kid, as they will assume that they get to say home if they say no, and it's not fair to you to dump an upset child first thing in the morning.
Also just rude, would you say "yeah I was really hoping she'd stay home today" when they came for drop off?