My other teen novel is entitled INVITATION TO THE DANCE, which is currently structured by the alternating voices of three sisters. The oldest one, Elizabeth, writes poetry, so her chapters are additionally structured by opening with a poem. I am considering revising based on the idea that two, or possibly three sisters, are actually the same person -- a twist at the end. These are different ideas based on Whicomb's suggested devices for telling a story:
The book could begin with an opening chapter that is not labeled by any particular sister to create suspense about who ended up "in the hospital after the crash."
This is an example of how it could be set up as a cautionary tale: "I’ve written this so I can figure out who I am, and maybe it will help you figure out who you are, too. I am in the hospital now after the crash and have time to sort it all out."
Show date and time before each chapter entry by one of the sisters. It will mislead the reader because although it looks factual with sequential dates, the years are off (2 years ahead for how Genny would be if she takes a certain path).
Although each chapter is currently written in first person from one of the sister's voices, it would become even more immediate if the chapters were written as diary entries.