Angelina now has a baby sister named Polly. Unfortunately, Angelina's parents are too preoccupied with Polly to give Angelina attention and are quite disorganized. Angelina then becomes jealous, frustrated, neglected and upset, and starts whining and crying as usual, and goes as far as to destroying her room out of jealousy because she feels like her family doesn't care about her anymore. Can the whole Mouseling family sort out the problem and reassure to Angelina that they still love her? Will Angelina accept her new sister?