Narrative secrets ahead.
As a young child, Jane believes in Neverland and enjoys hearing her mother's stories about Peter Pan. However, when World War II breaks out, her father is called to serve in the war and Jane is asked to take care of her mother and brother. As the war goes on, she becomes cynical and stops believing in both Neverland and Peter Pan. One day, an order comes that says that all the children are being evacuated to the countryside due to the dangers of the war. Wendy asks Jane to watch over Danny and tell him Peter Pan stories, but Jane refuses, belittling her mother's stories and her brother's faith in them.
That night, while Jane sleeps, Captain Hook, Mr. Smee, and the pirates show up and kidnap Jane (having mistook her for Wendy), taking her to Neverland in his flying pirate ship, the Jolly Roger. When the ship lands, Captain Hook uses Jane (still believing her to be Wendy) as bait to lure Peter Pan to his doom. He attempts to feed Jane to an Octopus but Peter Pan and Tinker Bell dive in and save Jane. Peter Pan soon discovers that Jane isn't Wendy, but is actually Wendy's daughter. Peter Pan excitedly assumes that Jane wants to be a mother like Wendy, and he takes her to meet the Lost Boys, which makes Tinkerbell jealous.
Jane soon arrives at Hangman's Tree, Peter Pan's hideout. Peter introduces Jane as the Lost Boys' new mother, but Jane refuses, as she is not good at telling stories. The boys attempt to get Jane to play a game with them, but Jane would rather return home. Jane builds a raft and attempts to sail home, but the raft sinks. Peter tells Jane that the only way out of Never Land is to fly out and he decides to teach her. Peter asks Tinker Bell to give Jane some pixie dust, but the stubborn fairy refuses, until Peter tells her that if Jane cannot fly, she will have to live with them. Tinker Bell complies and Jane is thrown off a cliff in an attempt to get her to fly. Instead of flying, she lands in a hole; Jane can't fly because she doesn't have faith.
Later, the boys find Jane's notebook and play with it, eventually ruining it. This makes Jane angry and she she proclaims that she doesn't believe in any of it, especially fairies. As a result of Jane's words, Tinker Bell becomes sick. Unless Peter and the lost boys can make Jane believe in fairies, Tinker Bell's light will go out forever. They decide to make her believe by making her the first Lost Girl.
That night, as Jane is sitting alone in the woods, she hears someone crying. Jane follows the sound and discovers that it is Captain Hook. Jane grabs his sword and points it at him. Captain Hook lies telling her that all he wanted to do was get his treasure back from Peter Pan who stole it. Because his men won't leave without the treasure, he cannot return home. Jane offers to get the treasure back if Captain Hook promises not to harm Peter, so Hook gives both his word not to harm a single hair on Peter Pan's head and a whistle to Jane for her to blow when she locates the treasure.
When Jane finds Peter Pan and the Lost Boys, she asks them to play Treasure Hunt with her. During the hunt, Jane starts acting like a Lost Girl. When Jane finds the treasure, she throws away the whistle and Peter and the Lost Boys make her the first Lost Girl. However, as they're celebrating, Tootles finds the whistle and blows it loudly. Captain Hook, Mr. Smee, and the pirates show up and capture Peter Pan and the Boys. Jane tells Hook about keeping his promise and Hook pulls off one of the hairs on Peter's head and gives it to Jane to keep. Peter angrily calls Jane a traitor and tells her about Tinkerbell's light going out.
heartbroken, Jane runs to Tinkerbell's house and finds her dying. Jane apologizes, saying that she believes in fairies. This revives Tinkerbell and she and Jane rush off to save Peter and the Boys. Jane and Tinkerbell arrive just in time as Hook is about to make Peter walk the plank. Jane steals one of the swords from the pirates and cuts the Lost Boys free while Tinkerbell manages to throw Mr. Smee overboard into the rowboat. Jane and the Boys throw Hook's treasure overboard, inciting the pirates to jump in after it. Hook chases Jane up onto the sails and tells her to give up. Jane refuses, telling Hook that he'll never win as long as there's faith, trust, and pixie dust. Tinkerbell sprays some pixie dust on Jane and she is finally able to fly. Peter, the Lost Boys, and the pirates in the row boat cheer for her. Jane frees Peter, but Hook grabs her. However, Peter manages to cut the rope. Hook falls into the water but Octopus quickly chases him back onto the ship. This makes the ship sink, but Hook manages to swim into the rowboat where he, Smee and the other pirates are forced to flee the Octopus.
The boys congratulate Jane for her victory, but then Peter says sadly that because she can fly, now she can go home to London. Jane tells the boys she will miss them, but that she'll always remember them. She also notes that now she can tell Danny all the adventures of Peter Pan and the Lost Boys. Peter and Tink escort her back to London. When Jane gets home, she tells Danny all about her adventures in Neverland and complimented on Tinkerbell's beauty, and Wendy is reunited with Peter for a short period of time. As Peter and Tink fly home, Jane says, "I'll always believe in you, Peter Pan". Then, a truck pulls up; Edward has returned home from the war. Jane, along with her family, goes to greet him.
To see pictures and screenshots of Jane, see Jane/Gallery.