Betsy-Tacy and Tib — Maud Hart Lovelace

THREE OF A KIND
Betsy and Tacy are best friends. Then Tib moves into the neighborhood and the three of them start to play together. The grown-ups think they will quarrel, but they don't. Sometimes they quarrel with Betsy's and Tacy's bossy big sisters, but they never quarrel among themselves.

They are not as good as they might be. They cook up awful messes in the kitchen, throw mud on each other and pretend to be beggers, and cut off each other's hair. But Betsy, Tacy, and Tib always manage to have a good time.

Ever since their first publication in the 1940s, the Betsy-Tacy stories have been loved by each generation of young readers.