Everything Shirley's new baby brother, Stanley, does is wonderful. Wonderful, that is, to everyone except for Shirley. What's so special about a baby that looks like a prune, has legs like a turkey, and drools? Only Ms. Mump, the baby-sitter, agrees that babies aren't that interesting, especially with their wet diapers, burping, and constant need for attention. But then Ms. Mump and Shirley discover that being Stanley's big sister is what's most wonderful of all.