Me (trying to think up a non labor-intensive Sunday morning activity): "How about you go collect some rocks in the backyard and then you can paint them!"
Them: "Yes!!! This is going to be SO fun!" (singing) "We're going to paint rocks, we're going to paint rocks!"
Check it out, lots and lots of colorful rocks:
(labor-intensive? nah... it was pure fun to paint those rocks and their clothes and their hair and their bodies and the dining table and floor, and the bathroom sink, and the tub, and the kitchen counter. what a perfectly restful sabbath-day craft idea, huh?)