I did manage to find those letters between Ninon de l'Enclos and Lord Saint-Evremond I mentioned during Happy Hour and a whole lot more. It's been years since I read their correspondence and I haven't read the rest of it, but from what I remember she was quite a woman.
Also, you might find interesting, Saint-Evremond's letter entitled: "To a modern Leontium".
Ninon de l'Enclos (archive.org)
Here is a good article on her on the Internet Encyclopedia of Philosophy: