It was Wendy's relationship with Peter and Tinker Bell's ensuing heartbreak that drove her back to Pixie Hollow in the books, although in the films Wendy was still a young child and neither one of them had met Peter yet.
Her father tells her that its time to grow-up which devastates both her, her mother, and her brothers. Peter Pan then comes and teaches them how to fly then takes them away to Never Land. Which makes Tinker Bell so jealous that she tricks the Lost Boys to shoot at her, almost killing her. Peter then takes her to the Mermaid Lagoon, where the mermaids bully her and almost drown her. He then saves Tiger Lily from Captain Hook making her jealous when Peter pays more attention to her at the Indian Camp. She then tells her brothers and the Lost Boys that it's time to leave, then Captain Hook captures them. Right when Wendy walks off the plank, Peter comes and saves them. Peter takes control of the ship and takes them home, the Lost Boys didn't come because they weren't ready yet.
Wendy: "Mommy! Guess what? Guess what?"
Mary: "Yes, Wendy? What is it, darling?"