Willey is a brave woman.
If she wanted to stay alive, she needed to go public in a huge way, so the spotlight wouldn’t allow BC and HC to get away with anything, should Kathleen’s car suddenly lose its breaks and she goes off a cliff somewhere.
Best thing she could do for self-preservation, to write the book and keep talking about the Perv and the Anabler to the Perv.
This is the only safe place for her! If she doesn’t “hide” out in the open, killing her would be easier.