Hi Andrea, classy hen travel in Paris sounds like a fab idea. I do love a sophisticated getaway with the girlfriends so this is going to be so much fun.
We do recommend the 7th district. If the price of the accommodation is no objection, then that's your district. Alternatively, you can consider the 8th which is more shopping oriented.
I'm sure it's going to be a fantastic time and you ladies will love it.