SOLVED. YA book about girl whose parents send her to underground nuclear shelter with two boys and one girl [s]

[Kristen]

I read a book a couple months ago about a girl who's parents know that some sort of disastrous event is going to occur so they send her to an unfinished nuclear shelter. Along the way she meets a girl and then two boys and brings them with her to the shelter. The book alternates between her keeping a journal of those events (I think) and the future where a group of kids are reading her journal and worshipping her as a sort of goddess. They use cheerleaders and jocks and other contemporary words like that to describe different groups of kids. I think the book may be part of a series and if so I want to find and finish the series but I'm not sure and can't remember the name in order to look it up and see. Thanks in advance for your help!!

[Kris]

Half Lives by Sara Grant?

[Kristen]

Yes! Thank you so much :)

[Kris]

Great! Glad you found your book. :)