I have a student who has the most amazing small child; this child, maybe five or six, has come to class several times now (snow days, like today, for example), and he quietly draws on the white board to the side of the room. (This is a small class, so it's not a distraction, and he's very quiet.)
Today, however, the student came in with his child, and said that perhaps he shouldn't bring the child to class because we're discussing the second day of "The Miller's Tale." But I said, sure, bring him in, since most of what we're discussing isn't specifically inappropriate to a small child, and I could circle the rest, I figured.
So that was the challenge of the day. And it worked pretty well (and we'll have a bit of time on Monday for anything more that needs to be said).
I'm not usually a big fan of kids in classes, but I'm pretty satisfied when they're occasional visitors, and well-behaved, and it makes it possible for the parents to come and participate in class. But this child is totally wonderful as a class guest.