"Ramona's world is changing. There's tiny baby Roberta at home, and as Ramona adjusts to being a big sister, she discovers that she likes teaching Roberta to do things such as sticking out her tongue. In fourth grade, she finally has a best friend, the new student Daisy Kidd (who is also new to the neighborhood). At school Ramona is frustrated with her teacher, Mrs. Meacham. Mrs. Meacham pushes her students to be proper spellers; spelling is a difficult subject for Ramona. Mrs. Meacham also intercepts a note that Ramona's friend Yard Ape wrote to Ramona; after that, Yard Ape is too embarrassed to play with her or even talk to her.
Beezus, a 14-year-old just entering high school, starts speaking French around the house, spending a lot of time on the phone talking about boys and asking her friends about who she should date, which makes her little sister mad. Ramona begins to feel forgotten by Beezus, while Mr. and Mrs. Quimby are always fussing over Roberta.
Beezus, in an act of rebellion, gets her ears pierced; her parents are amused and pleased that she is growing up. Beezus nervously attends a party at which boys were invited — as it turns out, the boys stayed outside the house the entire time and the girls hung out inside and everyone was happy.
Ramona and Daisy's dress-up play at Daisy's house ends in disaster when Ramona falls through the unfinished floor in the attic, dangling into the kitchen until Daisy's older brother Jeremy helps fish her out. Ramona is shocked that Daisy takes responsibility and Daisy's mother isn't upset. Later, she cares for the Kidds' cat when they go away on vacation for a week and she discovers that the responsibility of catsitting isn't as easy as it looks.
Ramona's rivalry with Susan, her nemesis since kindergarten, continues. Ramona is frustrated by Susan's perfect attitude. She reluctantly invites Susan to her "zeroteen" birthday party at the park at her mother's insistence. Susan brings an apple instead of eating the birthday cake, because of her mother's cautions about germs. After the other girls tease her and Mrs. Quimby comforts her, she finally decides to eat a slice of cake. Ramona discovers she feels sorry for Susan, whose mother expects her to always be perfect. Ramona gives the leftover cake to Yard Ape and his friends, who were also playing at the park, and she decides this is a perfect day - well, not perfect, but close enough."
