In Turtle in Paradise, the protagonist and narrator, whose real name is never mentioned, is called Turtle because she has developed a hard carapace of cynicism to protect her from the world, along with a tendency to snap at other people. These qualities make her an interesting and incisive narrator, though perhaps rather difficult to live with for those around her.
Turtle's mother, Sadiebelle, works as a housekeeper for rich people. This means that Turtle is used to moving from place to place, never having a home of her own, and that she has often encountered other children who looked down on her as the daughter of a servant. When she first arrives at her new home in Key West, she is independent, sarcastic, and unused to having friends. In Key West, she finds a family and a community of people who already know her mother and are disposed to accept her as one of their own.
Turtle also uses her intelligence to gain acceptance in the Conch community of Key West and the "Diaper Gang" run by her cousin, Beans. By the end of the book, she has become both more tolerant and more secure than she was at the beginning, since she now feels that she belongs in the community and is part of a stable, loving family.