Over the years, I've read lots of books like this: little corners of history, discovered by a non-historian, that somehow make it into published form. Sometimes the stories aren't terribly significant--the great significance is that wonderful primary sources have survived. But this book has a wealth of primary sources, plus an author that knows how to set these women in context.
It's a wonderful, wonderful book, and I wish more popular history books would take their cures from this book.