Jessi's Mom is going back to work! The dreded Aunt Celia is going to be living with them and taking care of Squirt. But she starts running the lives of Jessi and Beca too. She event lays out their clothes for them! One day Jessi is 10 minutes late home from helping Jacky Rodowski and she has to miss a BSC meeting! She and Beca start playing tricks on Aunt Celia to try and get her to leave. Meanwile, Jessi is taking over Jacky's science fair project. whenJacky does not win, she realizes that she was taking over just like Aunt celia- because she cared. All is resolved.
Aunt Celia made her first apperence in Super Specal 4: Baby- sitters Island Adventure when Beca got lost and Jessi's parents were not home.