As a multi-published, USA Today Bestselling author of novels set in 18th century France and contemporary France, I recommend you read books of that time period. Olivier Bernier is a good source. I’ll attach a link to a book he wrote about 18th Century Women.
https://www.amazon.com/Eighteenth-Century-Woman-Olivier-Bernier-ebook/dp/B07DDD2VPP
I also recommend you visit this blog:
http://leahmariebrownhistoricals.blogspot.com/
There’s a comment section on that blog and you could ask specific questions.