In Behind every mean girl...There's a tragedy, all of Rachel's issues come back around to one word - forgiveness. She spent so long holding on to that hurt that she no longer knows how to forgive nor should she forgive.
I've made a playlist of some songs I believe can give her some insight about forgiveness and maybe clear her path a little. I've even arranged it so she knows which of the two men who deserted her would dedicate the songs to her.
From Darwin Reel - the uncle who chose blood over morals:
Beautiful war by Kings of Leon
Blank page by Christina Aguilera
Low Man's lyric by Metallica
From Brandon Matthews - the scared ex best friend:
Let's stay together by Al Green
Please forgive me by Bryan Adams
Sorry's not good enough by McFly
And obviously Rachel would never take them and be happy. The Rachel Jackson we all know would certainly have a thing or two to say about forgiveness to these men who betrayed her innocent trust.
How you like me now? by The Heavy
The heart of the matter by Don Henley
Getting away with it (all messed up) by James
Take back by Adam Lambert
I believe these last two would be something that would relate to her feelings towards the ending of the book.
Ghosts that we knew by Mumford&Sons
Forgiven me by Mary Mary
Seriously, I think this would have been Rachel's theme song if she had a choice. How you like me now? by The Heavy