Death has leaked into every part of Macy's life, so much so that she lets her dad's death define her entire being. She can't seem to deal with her grief and move forward with her life. But by the end of The Truth About Forever, mortality is defining her actions in a different way. Now it's about forever being now. Macy doesn't want to waste her precious time being miserable, so she chooses to live again. Much better.
How each character in The Truth About Forever deals with death tells us a lot about who they are as a person.
Deborah still hasn't completely gotten past her husband's death by the end of the book.