I cannot find anything about her.
From the Osenat Web via pinterest.com/bohemianbelle80/portraits-1810-20/; cropped frame from all sides and filled in shadows.
The A-line skirt is very 20s and the waist band just a few com below the bust suggests early 1820s.
Keywords: Kinson, Jenny Cécile de Maillé, Marquise de Lubersac, Marquise, French, curly coiffure, curly bun, poke bonnet, straps, bows, modesty piece, sweetheart neckline, bodice, scoop neckline, epaulettes, quarter length full sleeves, brooch, waist band, Empire low waistline, maxi-length A-line skirt, flounces, shoes, hosiery, gloves, wrap