Now that I've actually started paying attention, I've noticed that there are quite a few retellings of Peter Pan knocking around out there. Girl Lost if both a retelling (in this version only Gwendolyn, "Gwendy", goes to the island - no brothers - as well as other changes) and a continuation (all of the characters involved are older and pursuing a new phase of their lives). 
 Barely out of her childhood years Gwendolyn Barrie was travelling with her parents on their yacht when pirates boarded the boat and murdered her parents, leaving her alive. Three weeks later the authorities found the sole survivor, but Gwendolyn was convinced that she'd spent months on an island with "the Boy". Unable to account for the missing time, Gwen accepts her family's hypothesis that she must have invented this island, this Boy, as a coping mechanism for the horror she'd been through. But the Boy still haunted her and Gwen spent the next several years of her life in and out of psychiatric facilities, her hold on her sanity tenuous at best. 
 Now that her younger brother, Micah, is old enough to attend university, Gwen has been allowed to go with him as an experiment to prove that she is able to hold her own out in the big wide world. She's understandably nervous and as the reader you get a real feel for just how insecure Gwen feels in social situations, how worried she is that she'll make a wrong move and end up having all freedom taken from her forever. 
 Then in one of her classes Gwen meets Peter, a young man who looks much like an older version of her Boy, and really starts to question her sanity. Matters are made that much worse when Peter starts a relentless pursuit of her and she finds her carefully constructed walls crumbling as he awakens desires she shouldn't feel and memories that should not exist. 
 I didn't always fully understand Gwen: she seems very introvert and wants to stay out of the spotlight, then she's going to a nightclub wearing little more than nothing. I can understand picking fights and lashing out, but I find it harder to accept actions that seem out of character. It's a shame because other than these odd scenes the author has a really good story going here. 
 Gwen is trying very hard to be the woman her aunt and her psychiatrist want her to be so that she can take over as head of Barrie enterprises when she comes of age (though don't ask what Barrie enterprises does as this is not addressed). Peter is a curious mix between young man and young boy with his pack of lost boys as well as Belle following him as he pursues the one thing he's ever wanted more than eternal childhood. 
 The way the story ends doesn't allow for any sort of conclusion to the events of the book. Luckily a novella sequel was released in late 2014 that allowed for more closure. 
 Girl Lost was by no means a perfect story, but it was one that I enjoyed for what it was.