Marion has always wanted to babysit her sister but her parents have said she is too young! When they finally ask Marion to watch Gabby during a party at their house, Marion can t wait! But she quickly finds out that babysitting isn t as easy as it looks. Gabby won t listen to Marion at all. After getting upset about losing a board game, she makes a total mess and even draws on the table! When Marion gets called to the Critter Club to help out with a run-away cat, Gabby tags along and causes even more trouble! Maybe being a sister is better than being a sitter.