Nana is very caring toward Wendy, John, and Michael Darling and treats them as her own puppies. They cherish her as an important relative. When she was taken to her dog house for the night, it was considered a cruel punishment for them. Even when George took her there, he felt sorrow after seeing her saddened face. She is in charge of Wendy, John, and Michael's health, giving them medicine presumably every night.
Nana is first introduced as the Darling family's nursemaid. She was first seen doing her daily duties; cleaning the nursery and putting away Wendy, John, and Michael's toys and games. When Wendy is told she must grow up, she was shocked by the decision. When George begins to storm out the room, he trips over her. Both fall, but the rest of the family only comforts Nana. George is shocked, and this causes Nana to be taken to her dog house. As she was being dragged by her collar, Michael holds onto her tail trying to stop George from taking her to her dog house, but Mary kindly stops him by picking him up and she waves at him sadly. She is heartbroken, as she never sleeps in her dog house. George feels sympathy for her but claims Wendy, John, and Michael are not puppies and she is truly a dog. During the song "You Can Fly", Peter Pan took Wendy, John, and Michael on a trip to Neverland, and Nana spots them flying out the nursery window with him. She is horrified and tries to stop them. Michael spreads some of Tinker Bell's pixie dust onto her. She begins to fly but is held back by the leash still attached to her collar and is left waving at them. When they return home, she is happy to be taken back to the nursery, as George finally realizes he's been too hard on her and Wendy. She joins Wendy, George, and Mary as they watch Peter Pan fly away on the Jolly Roger.
Nana appears as an audio-animatronic figure in Peter Pan's Flight. She makes her most notable appearance in the nursery, next to the letter blocks that constantly fall, as she attempts to stack them, and outside next to her doghouse.
Originally, Nana was going to journey to Neverland alongside Wendy, John, and Michael and have a comical subplot chasing after Tinker Bell. She was also intended to be the film's narrator. While she was dropped from that side of the story, she was given a notable role in the opening and ending of the film, becoming a beloved character from it. However, she did go to Neverland with Wendy, John, and Michael in the Jake and the Never Land Pirates movie, Battle for the Book.