The Summer Before by Ann M. Martin
Release Date: April 1, 2010
Before there was the Baby-Sitters Club, there were four girls named Kristy Thomas, Mary Anne Spier, Claudia Kishi, and Stacey McGill. As they start the summer before seventh grade (also before they start the BSC), each of them is on the cusp of a big change. Kristy is still hung up on hoping that her father will return to her family. Mary Anne has to prove to her father that she's no longer a little girl who needs hundreds of rules. Claudia is navigating her first major crush on a boy. And Stacey is leaving her entire New York City life behind...
...in order to find new friends in Stoneybrook, Connecticut.
The Summer Before . . . is a sweet, moving novel about four girls on the edge of something big - not just the Club that will change their lives, but also all the joys and tribulations of being twelve and thirteen.