A Diary of The Lady by Rachel Johnson is an account of her time as editor of The Lady magazine. She is the sister of Boris Johnson, a columnist for one of the broadsheets, and a novellist. I got about a quarter of the way through before abandoning it.
I stopped reading because I found the writing dull and leaden. It could have been an interesting, funny story, but Rachel Johnson contrives to make it and herself come across as boring and unpleasant. Give it a wide berth.