She literally wrote a book? Wow, that's hurtful. Sorry.
Sorry, I've expressed myself badly there. Her friend has written a book, and I think the friend is a strong influence on my wife, saying "It's okay to leave your marriage, I've done it already, you can too."
My W was asked to take a break from the singing ministry at our church because she was telling everyone she had separated from me and how good that was. She took it as a sign from God that she should leave the church! She now drives an hour each way on Sundays to attend a church where this other lady is. D14 goes with her. D14 will no longer go to our old church, telling me that everyone there is "fake". I don't think this is an opinion D14 has formed on her own.
My feeling was (note, was) that my W has read the book written by her friend and then retrospectively mapped things in it back onto our relationship, even if they weren't there - sort of like the old jokes about people looking up symptoms on the internet/in home remedy books and suddenly thinking they have all sorts of illnesses. My W had already done this back in 2018, when she showed me a book that 'proved' she had a cold because of things I had done in the past. W had made a comment to her dad months ago about "only just coming to terms with what went on in our marriage". It mystified me at the time but when I learned about the book, it seemed to me it must be the explanation.
I do agree with the above posts about my W having some valid points. I'll come back and post on that later today.
