I draw my family a lot, and they’ve all gotten pretty used to it and don’t grumble much, although my husband has objected to the number of sketches I’ve drawn of him holding a beer.  But that’s when he tends to hold still, when he’s done working in the garden and comes in for a refreshing beverage and to check on the ball game.  As for kids and pets, they’re most easily drawn when they’re asleep.