What I personally believe happens after TFiOS ends
I kinda went a bit too into it :P
Hazel does die, maybe a year or two later.
It’s silly to think that she might have gotten better, but you can think that if you want. I just know if it was real life she wouldn’t have.
She and her family are really comfortable though in that last time. Augustus left her feeling somewhat complete and her parents are grateful that she had him when she did.
Of course she mourns him but I think when she knows that she too is dying she just is thankful for her time with him.
In her final time she writes him letters and maybe even poems.
As for Isaac he finally moves on from Monica. When he is used to his life being blind he meets another girl and falls in love. When Monica hears he has a new girlfriend she contacts him saying she loves him and he has the pleasure of telling her to piss off.
Hazels parents are heartbroken when she dies but since in her last few months she was so vocal about how she wants them to be happy after her death they try their best to remember how great she was. As well as writing letters to Augustus she had written some to her parents and they have them framed and read them everyday.
Hazel’s mom becomes a great social worker and starts up a support group a lot better than the heart of the cross one.
Peter Van Houten appears at Hazel’s funeral completely sober and tells Hazel’s parents he has been for months. He is currently writing a new book.
