I'd say go with her. Usually, the character has the last say. She can still have her revenge by watching the bad guys get what's due to them. Unless you want the general theme to be revenge. For that, you'll need an angry, determined, and somewhat ruthless protagonist. With what you have written in the post, it seems your protagonist is a survivor and a nice person.

If it works better for you, dividing the story in three parts is fine. At this point, I am dividing mine inside my mind, too. Otherwise, I can't think straight.