Our old friend Arthur and has little sister D.W. await a new baby. Friends tease (""Better get some earplugs""), Mom gets out their baby pictures, and D.W. learns how to diaper dolls. After Kate is born, D.W. takes over, and Arthur is, a little forlornly, aloof till the day D.W. fails to comfort Kate and Arthur cheers her up with a burp. Nothing extraordinary here, but nice, solid, cozy reassurance. The illustrations are cheerfully humorous, clear enough to be ""read"" by quite young children or shared by a small group; the text is simple enough to double as an easy reader. A good addition to the many books on this important subject.