I found an interesting little tidbit while doing research on morganatic marriage last night. The County of Auvergne is a real title, and as such belonged to real people, though it had died out by the time of Olympe's birth in 1750. It was resurrected, however, in 1773 for the Comte d'Artois, the brother of Louis XVI. He only held it until 1778, when he exchanged it for the County of Poitou.
Apparently he liked that one better; it probably had larger tax benefits.
I am a university professor and costume professional who calls Virginia home. Interested in costume history, and history in general, I endeavor constantly to better understand life through those who lived it.