One thing that does seem to be more clear is that some of these costumes were actually costumes - fancy dress, stage, or ballet costumes - and have to be though of differently than normal dress. This is the case with my portrait here:
|Mademoiselle Guimard by Jean-Baptiste Greuze, 1790.|
Marie-Madeleine Guimard was a French ballerina and the star of the Paris stage for a whopping 25 years. She was immensely popular and also quite rich, being admired and supported financially throughout her career by aristocrats, clergymen, and royalty, hence the many portraits of her, often depicting her as characters she portrayed, such as Terpsichore:
|Mademoiselle Guimard as Terpsichore, by David, 1773-1775|
Anyway. Back to what she's wearing.
Here's the second link. Two, actually (these were pointed out by Dennice again, with large version from Cassidy's valuable blog):
Above - Costume for Idamé, in the Orphan of China (1779) - boy this looks a lot like a version of Guimard's dress, but is from 10 years earlier. Note on The Orphan of China - it was originally a Chinese play titled The Orphan of Zhao, and was adapted throughout Europe, in this particular case by Voltaire, and performed on stage for the first time in 1755 by the Comedie Francaise. You can read more about it here.
And here we have Costume of the Sultana used in the Comedie Francaise in the plays where there is a role for this costume (1779). Again, 10 years prior but very similar, although depicting a Sultana rather than a Westernized Chinese woman. Clearly the French didn't distinguish.
Guimard was indeed a member of the Comedie Francaise. She may be depicting an archetypal character in her portrait, and the costume could very well be her own - did she portray Idamé around 1789, or a Sultana in one of her last performances? I'm still searching for that evidence...
Madeleine Guimard retired from the stage in 1789, at the age of 46, and weathered the oncoming Revolution. The 1790 portrait seems like the last whimper of Guimard's life and career before everything changed for her, the Opera, and the country. She died in 1816.
What a fascinating, chewy bit of history. I'm even more interested in this costume now that I know more about where it may have come from, and the woman who wore it.
You can read more about Marie-Madeleine Guimard in The Art of Ballet, and Ballerina: Sex, Scandal, and Suffering Behind the Symbol of Perfection.