When George discovers Wendy is once again telling what he calls "silly, impractical stories" to her brothers, he kicks her out of the nursery as the "final straw" in his discussions with her, stating that she will have her own room by presumably the next night as part of her maturity. At the end of the film, unlike the events of the novel and 2003 movie adaptation where they are awake and flying into the nursery window, Wendy and her brothers are revealed to have been sleeping the duration of their parents' absence, with Wendy mysteriously asleep at the window seat. A cloud shaped like a galleon sails across the moon a short time later, after Wendy wakes.
The nursery makes a reappearance in Return to Never Land, repurposed as Jane and Danny's bedroom, though the sequel has many inconsistencies and continuity problems. It also appeared in Tinker Bell, albeit much smaller as John Darling and Michael Darling have not been born yet and Wendy is Michael's age. The nursery also made an appearance in Once Upon a Time, albeit configured a bit differently and with colors more closely matching the 2003 Warner Brothers film's version rather than the Disney version, though the dormer, window seat, and French windows are still there.
Definition of nursery
In Victorian and Edwardian times, for the wealthy and middle classes, a nursery was a room or suite of rooms, usually at the top of a house (where the roof is), made for the purpose of caring for a family's children. Sometimes, this would include the night nursery where the children slept (with beds, as most often depicted), and a day nursery where they ate and played, or a combination thereof (as depicted in the Disney movie). The nursery suite would include some bathroom facilities and possibly a small- to medium-sized kitchen for the preparation of the children's meals. Like in Peter Pan, children who became too old to continue their care in the nursery are assumed to have got a separate room when they became old enough to leave. In the Victorian and Edwardian household, the children's quarters were referred to as the nursery, but the name of the responsible servant (or servants) had largely evolved from 'nurse' to 'nanny'. The Nursery Maid was a general servant within the nursery, and although regularly in the presence of the children, would often have a less direct role in their care, unlike how Nana is portrayed as being very much involved in the movie. The nursery maid reported to the nanny (or nurse) and assisted her in taking care of the children of the employer's family, her duties including tidying and maintaining the nursery, lighting the fires in the nursery during wintertime, and carrying meals, laundry, and hot water between the nursery, kitchen, and scullery. It was a junior role for young girls in real life, working under the supervision of the experienced and usually older nanny. Nursery Maids typically wore a uniform, similar to the other maids in the household. In 1845, for instance, the satirical magazine Punch published a guide to domestic servants in which it suggested that any girl could undertake the duties of a Nursery Maid, as every girl had the requisite training of "snubbing and slapping" either her own siblings, or the siblings of other people. Domestic service agencies supplied nursery maids and sometimes gave basic training, for which popular manuals were also published.
It is unknown if Mr. Disney created a floor plan for the nursery when he made the movie, how big the room actually is, or how big such a room would be in real life, but from what is shown in the movie it is quite enormous as aforementioned; in fact, the entire Darling family can be in one area of the room and there would still be plenty of space behind them.