Mary is a very kind, beautiful and understanding wife and mother. Although she didn't entirely believe in Peter Pan until the end of the film, she believed in the spirit of him. She was deeply concerned about Wendy, John, and Michael's well-being, especially Wendy's, who was being forced to grow up too soon by George. She always tried to keep the peace in the house, shown when she tried to keep George from losing his temper with Wendy, John, and Michael.
Mary, referred to as Mother by Wendy, John, and Michael, appears at the opening and ending of the film. She does play an indirect role in the film, as she is alluded to throughout the picture. She is shown to be very caring and loving. She doesn't seem to agree completely with George's overly-practical ways, however.
The opening narration tells that Mary believes that Peter Pan was a "spirit of youth," showing that she believes in him to some extent, in contrast to her more practical husband, George (and, in Peter Pan and the Sword of Mercy; a book from the Starcatchers series that ties in with the original Barrie novel, it is revealed that they went to Neverland themselves as children, but the time of the film, George has forgotten about those times). She is shown getting ready to attend a party alongside George and attempts to calm him down as he grows more angry and impatient due to Wendy, John, and Michael's antics. She fails, though, as he grows so annoyed at the make-believe (and thus impractical) games Wendy, John, and Michael are playing, he abruptly decides that Wendy must move into her own room. This visibly shocks her, and as he leaves, she puts Wendy, John, and Michael to bed, comforting them about George's behavior (telling Wendy not to worry about growing up anymore and assuring the boys that George was only upset about his cuff links and that Nana will be fine). As Wendy falls asleep, she asks that the window is left unlocked, as Peter Pan will want his shadow that she had been keeping. This worries Mary a bit, and as she and George leave for the party, she mentions it to him.
During the film, Wendy alludes to her several times, most importantly during the song "Your Mother and Mine", where she reminds the Lost Boys of their mothers after she realizes that John and Michael are forgetting Mary. She also notes that should the Lost Boys decide to return home with them, that Mary would most likely be glad to have them.
Mary appears at the end of the film, having returned from the party. She is shocked to find Wendy asleep on the window seat rather than in bed. She calms Wendy down, who excitedly begins to recount her dream and what it has taught her. As the film closes, she watches a cloud shaped like a pirate ship, along with Wendy, George, and Nana, after George recognizes it from his childhood.
Mary doesn't appear in the sequel. It is presumed that they have either moved into another house or have passed away since Wendy, her husband, Edward, and children, Jane and Danny, are living in the Darling home.
At the end of the film, Wendy was given her lost ballerina and rushed to show Mary. She is then heard.
Mary and the rest of the Darling family appear in the second season of the ABC fairy tale drama, Once Upon a Time. She is portrayed by actress Karin Inghammar. Her attire differs vastly from the film. In this, she wears a yellow colored dress, whereas she wears a light pink one in the film. Her facial structure and hair color make her look similar to Olivia Williams, who portrayed her in the 2003 Universal film. She is the one that says good night to Wendy, John, and Michael every night when they go to sleep. She was briefly Baelfire's adoptive mother until he went to Neverland.
- Mary's voice actress, Heather Angel, also voiced Alice's sister in Alice in Wonderland.