11-year-old 6th-grader Margaret Simon adapts to her new home as she makes and shares secrets with friends, keeps up with her grandmother, and begins to experience some of the changes leading up to adolescence. She is not pleased when her parents announce they are moving from New York to a small town in New Jersey. Her paternal grandmother, with whom Margaret is close, remains behind in New York, though Margaret is pleased to see her visit at just the right times throughout the book, and Margaret is also able to visit her grandmother in New York a few times.
Margaret makes friends relatively quickly. She and three other girls form the Pre-Teen Sensations (the PTS's), a secret club of friends that share everything. They gossip about boys, other students in their class, their new 6th grade teacher Mr. Benedict, and the changes they anticipate or experience as they approach their teenage years. As the new kid on the block, however, Margaret doesn't always like sharing everything, and sometimes feels she's the odd one. Everyone seems to have a religion, for example, except for her. She, on the other hand, was raised with no religion because her two sets of grandparents were so dogmatic in their Christian and Jewish faiths respectively that they drove Margaret's family crazy. Margaret sometimes prays in her own style, and tests out a few churches and her grandmother's synogogue during the year. Though the leader of each temple or church seems quite eager to convert her, she is not attracted to any one of them, and concludes that she is better as she is, without a religion.
At home, Margaret has supportive parents, though not everything always goes perfectly. When her mother decides to unilaterally send a Christmas card to her estranged parents after 14 years (they were angry at her for marrying a Jew and not a Christian), they suddenly write to announce they will be visiting right during Margaret's purported spring break trip to Florida to visit her other grandmother (who has by now moved towards fairer weather). Margaret is furious. When this grandmother tries to tell her she is Christian, Margaret storms to her room and will not come out. The next evening, her maternal grandparents leave. Margaret is not unhappy to see them gone, but is even more angry at them for wasting her previous vacation. Fortunately, her paternal grandmother shows up, having decided Margaret could use some support. Her other grandmother is gone, but the two are able to enjoy each others' company.
Margaret's further adventures include a dinner party (complete with nerve-wracking girl-boy middle school games like spin the bottle), working with classmates she doesn't particularly like, and turning in her individual project on religion. Each experience helps her to grow a little bit more, which is exactly what she was asking God for throughout the book; she just didn't realize that this was the sort of growing she needed. As the book ends, she begins menstruating – the physical sign she's been waiting for that she is indeed growing up.
Best part of story, including ending:
I don't like how the girls' group seems a bit gossipy.