Margaret befriends Nancy, a neighbor girl her own age who seems confident and knowledgeable about many subjects, including sex. Nancy, Margaret, and two other girls, Gretchen and Janie, form a secret club where they discuss subjects like boys, bras and menstruation. The girls anxiously await their menarche, prepare in advance by buying belted sanitary napkins (changed to adhesive pads in later editions of the book), and do exercises in hopes of increasing their bust measurements. Gretchen and Nancy have their menarche, causing Margaret to worry that she is abnormal for not having started yet. Margaret envies her classmate Laura Danker who, unlike herself, already menstruates and, according to Nancy, is involved with a handsome older boy. Margaret is also attracted to a popular boy in her class named Philip Leroy and kisses him at a party while playing Two Minutes in the Closet (a game similar to Seven Minutes in Heaven). Over time, Margaret discovers that her seemingly confident friend Nancy has her own insecurities and doesn't always tell the truth (she had told Margaret she got her menarche on vacation before she really did later at a restaurant with her), which puts Margaret in several uncomfortable situations.