When Samuel announces during show-and-tell that he is going to have a baby, it incites a rash of “pregnancies” in Mr. Donald’s kindergarten class. Both the girls and boys are expecting, some trying to outdo the rest with talk of twins, triplets and even a beagle. All week, Samuel teaches his classmates about caring for a baby—how to support babies' heads and how to diaper them (you can’t hold your nose, because you need two hands). The concerns they bring up bother him a little, but his own worry is larger: Will his new brother or sister like him? Throughout, Samuel’s friend Marcel provides loving support and reassurance. And after a week of vacation, Samuel has a new sister for show-and-tell. Wummer’s pencil-and-watercolor illustrations charmingly portray the innocence and enthusiasm of her multicultural cast of kindergarteners, shirts not quite concealing doll arms, dinosaur tails and truck wheels. A just-right mix of sweetness and humor that is sure to strike a chord with young children expecting a baby of their own. (Picture book. 3-6)