Just as Long as We're Together (Best Friends)
Judy Blume

Stephanie’s best friend is Rachel. Since second grade they’ve shared everything, good and bad. Now, as they start seventh grade, Stephanie meets Alison, who has just moved to their neighborhood. Stephanie hopes all three of them can be best friends, because she really likes Alison. But is it possible to have two best friends? Or is it true that two’s company, three’s a crowd?
From the Paperback edition.