One might think "French Empire", but she's earlier. Late 1700s, after The Terror, to perhaps c.1810. She might also be among the wealthy young Incroyables et Merveilleuses whose elaborate fasion political movement, c.1795-99 is one quite unparalleled in time - worth reading about. We know for certain she was a Royalist protesting the upheaval of the lives and fortunes of Kings and Nobles in the time of The Terror, when so many met their end at the guillotine. The portraits of this era with blood red shawl or scarf linked these people to those lost - perhaps a relative, closer to them than the ill-fated King Louis XVI and Marie-Antoinette. The portraits are somber, a hint of defiance, and quite often done by French artists alongside the Nobles, most living in exile for decades, waiting restoration of the Royalty. I've long collected these mourning Royals' portraits. Most don't even understand what's being said in them. Measurements noted on the photos.
Very good to excellent condition, a portrait with backing so thin in depth, I feel certain it was originally mounted on a snuff box. While the old snuff box must have been broken, the young woman's portrait has been long and well-treasured. No flaws to note on the painting, wafer, convex cover glass nor the frame mount which has that thin plaque of gold attached to the brass mounting (see images - it's visibly thicker than gold plating and was not so unusual on these finest portraits of Nobility, 1700s to earliest 1800s. On back of the wafer you see the original old foil remains in place. Those pieces were there to reflect even more light up through the super-thin wafer, to light the skin. Superb detail, painting, though we have no signature of the artist and no ID of this beautiful and defiant young woman.