The writing on the oiled paper back surely would tell her story, but I really can't make it out. It might be Marquise St. Yves. But I find nothing to help me with that. Someone's mistress, perhaps - likely, this beautiful redheaded young woman is elaborately posed in a French room with complex and elaborate striped silk drapery and upholstery, and one is caught up in the flowing color and silks of the robe and room, and it does take a moment or two to find the eye's and lover's message as her open bodice reveals her. She's the picture of a time, really - France, nobility, c.1770-1800, really, until lives were changed by the French Revolution. I digress. Her portrait, beautifully done in gouache on thin wafer, has a subtle calming palette and evidence of a strong talent in the artist, who has simply signed, "Villers". My research gives a question of the artist perhaps being Marie-Denise Villers, who did numerous interior portraits one might connect to this in manner and in attention to fabrics, folds, and palette, paintings of women. But I am not positive.
Very good to excellent condition for age and type, the painting is 3 1/2" in diameter, perfectly preserved in it's original frame, 4 3/4" square and 1/2" in depth. The cover glass is likely a replacement, is flat rather than the more typical convex, and is clean and clear and gives a perfect view of the little painting. Her face is only 1/2", chin to hairline. Imagine! Well treasured for 250 or more years. You have a look: Marie-Denise Villers (née Lemoine; 1774 – 19 August 1821).
