Mystery novel about woman who buys a book and discovers it is about her.

A woman buys a novel, goes home, and starts reading. She is shocked to find that the book is actually about her. I am struggling to remember the author and title. I think I read it in the 1970's or 1980's. Thank you.

I think there is a similar plot in If on a Winter's Night a Traveler by Italo Calvino.

The Calvino book sounds interesting, but not the one I'm looking for. Thanks for your input.

Bumping because I'm interested in finding out about this one