Two childhood friends and one gets jealous of the other and sets her up to make her look bad

Two childhood friends one from a good home and one not and the good family loves her friend and she ends up jealous of the one from a bad home. As adults one gets in an accident and is in a coma, she can hear everything but nobody knows that. It goes back and forth between their childhood and what’s happening in the hospital. It refers to a journal (maybe a flashback she isn’t sure it was a journal) that one of them kept and there is a twist at the end that the girl you think is the good one is actually the evil one and that she set fire to her home or something. Any help is appreciated my mom can’t remember the name of this book! She thought it was a Colleen hoover book at first so maybe it gives a similar vibe.