AN: this story is influenced by the 2003 Peter Pan movie and also Syfy's Neverland, but it shouldn't be too hard to follow. And the story is meant to be taken with a whimsical tone to it, not firmly grounded in realism. Keep that in mind.
And I'm posting this because it's the only way to make myself finish it :)

Older sisters can either be the kindest of creatures, or the scariest. At certain times of the day, Olivia Darling was both. Her younger brothers and sister knew this full well. She was just home from finishing school for the Christmas holidays, and sometimes she would join into their games of make-believe. Olivia could fight off pirates with the best of them, frightening even Wendy with her ruthless swordplay, but when John or Michael (most likely Michael) stepped onto the hem of her dress and ripped it, she would immediately tell them that it was quite all right and that it was just a silly dress in the nicest of ways.

Mr. Darling wondered if that school was doing her any good, since she came home and acted just like her younger brothers and sisters, but Mrs. Darling watched her at dinner and at parties that Olivia sometimes accompanied them to since she was old enough (eighteen was quite old) and she always behaved in a Perfectly Proper manner, being polite to absolutely everyone. Mrs. Darling wondered if there mightn't be boys come calling soon.

Wendy asked Olive, as she called her, about this, and Olive told her that boys were absolute bosh and only a very, very good one would ever be the one to come calling for her. Whenever Wendy would ask how she knew the good ones from the not-so-good, Olivia would always tell her the same thing: "I have to wait and see. The not-so-good ones' acts will slip after a while; the good ones' never do."

Wendy liked Olivia very much, and Olivia liked Wendy, so when Wendy told her about the boy in her window and the shadow in her drawer, Olivia did not tell her how foolish she was, nor to shut and lock her window. She did not go running to the other grownups either, which would be a very meanish older sister thing to do. She told her to wait and see about the boy.

She also told her to keep her cutlass handy, but then, that is an older sister thing, too.

When Wendy began to come up with new stories, the grownups didn't think much of it. After all, Wendy always had an imaginative mind, so new stories about Indians and pirates and a boy who could fly did not seem too out of the ordinary. Mrs. Darling, who had seen into Olivia's trunk as she had unpacked it, rather thought Wendy got her ideas from her, for Olivia's trunk was full of books like Arabian Nights and Last of the Mohicans and Treasure Island, all books that Wendy would like. And indeed, Olivia did read those books to her younger brothers and sister, but Wendy's stories were so much more magical than those.

John and Michael knew the stories were true, but grownups never believe children when they say such things.

This one particular night, Olivia was up in the nursery sewing one of the sleeves back onto John's shirt. It had come off in a particularly fierce sea battle between Captain Hook and Peter Pan, with Hook being John.

"But I had to, Olive," Michael insisted, "I had to cut off his hand! That's how he becomes Captain Hook."

"I know, Michael," Olivia said patiently. "But John's hand is much further down the sleeve than this tear in the shoulder."

"Michael just isn't very good at swordplay," John said, with a worldly air.

"You just didn't do it right," Michael insisted. "You dodged!"

"Well, if I was Hook, I'm not going to make it easy for you to cut off my hand, am I?" John countered, pushing his round glasses further up on his nose.

"Nana's here!" Wendy announced, opening the nursery door for the large dog. Nana was a special pet of the Darling family, and in fact regarded herself as something of a nurse or surrogate mother for the boys, since she had come to the family when John was just a baby. Michael proclaimed her the smartest animal that ever lived, and Olivia sometimes thought him right.

Nana trotted over to the table that held the glass bottle of medicine and barked once.

"Oh, do we have to, Nana?" Wendy asked, setting down the book of fairytales she was reading. "It is such beastly stuff."

"She says yes," Olivia said. "Go on, now."

Wendy was rather a responsible child who didn't whine (much), so she could be counted on to screw up her face and gulp the spoonful down on her own, which she did. The boys required more persuading, which Nana was all too happy to provide. While she attempted to herd them towards the bottle, Wendy sidled up to Olivia, who was putting the last few stitches into the shirt.

"Olive," Wendy said, "I heard mother and father talking about giving me my own room."

"Really?" Olivia asked, biting off the end of the thread and shaking out the shirt. Now it just needed to be laundered rather desperately, and then it would be as good as it was ever going to get.

"Yes," Wendy said, hesitating. Then, "Olive, does this mean I'm growing up?"

"I expect so," Olivia said, looking over at her. Her dark brown hair was pinned up on her head like a young lady, not hanging down around her shoulders like Wendy.

"And I must learn to be a lady, and go to finishing school like you?" Wendy added.

"Not right away, but soon," Olivia said.

"I'm not sure I want to be finished," Wendy said quietly. "I'm not sure I want to ever grow up."

"Can I tell you a secret, Wendy?" Olivia asked, smiling at her.

"Yes," Wendy said, opening her eyes wide. Secrets from her sister were the best kind.

"I don't think people ever really get finished," Olivia said. "I'm not. I suspect it takes a whole lifetime to get finished. So you needn't worry."

"Oh," Wendy said. It was some comfort to her, but the prospect of a lifetime ahead of her was a bit scary. "I still don't want to grow up."

"No one can make you grow up if you don't want to," Olivia told her absently, folding up John's shirt and throwing it with practiced aim at the laundry basket.

Wendy nodded to herself, as if she was working out something in her mind. That night, her stories were all about a secret place where Peter Pan, the boy who could fly, lived with his Lost Boys that never ever aged, and had great and grand adventures with the inhabitants of that place.

"But he comes here sometimes," Wendy said, "By use of a portal between that world and ours."

"Where is it?" Michael asked in a hushed voice.

"Hidden," Wendy whispered. "Far in the East End of London. The only marks to point the way are concealed in a secret treasure map. And if you strike the portal just right… you would find yourself suddenly in Neverland."

Olivia just smiled.

When Nana raised a hue and cry during the small hours of the morning, and Mr. and Mrs. Darling dashed into the nursery to find all the beds empty and the window open, Olivia was the only one with the sense to keep the window open and discover that all the small iron cutlasses were missing from their usual places. And so, though she was worried right along with her parents, she knew that nothing untoward had happened to her siblings. They were simply in another place, having a wonderful time.

Or so she thought.