Annie, her dad, and her bunny, Snowball, love living next door to her cousin Henry, his parents, and his big dog, Mudge. But something is missing. Annie wants her dad to find someone to love. Then her dad meets a woman named Martha and falls in love. Annie is excited that Martha makes Dad so happy, but she is a little worried about meeting her for the first time. Before long, Martha feels like part of the family, and it's time for a wedding! It's a big change to have a stepmother, but Annie knows that all their new family needs is love.