Jessica Wakefield loves her neighbors' new baby girl. She and her twin sister, Elizabeth, think it would be wonderful to have a little sister of their own. And when Mrs. Wakefield begins to buy baby clothes and things for a baby's room, the twins wonder if their mother is pregnant! Just in case, Jessica decides to practice being a big sister by baby-sitting newborn Jenny. That's when she finds out that taking care of a baby isn't all fun and games!
