This may be Karoline Sophie Wilhelmine zu Leiningen, whose genealogical sketch is here.
From jeannepompadour.tumblr.com/post/89959538145/caroline-countess-zu-soms-wildenfels-saxonian.
Her skirt may be in keeping with revolutionary France, but her bouffant coiffure is ancien régime.
Keywords: Karoline Sophie Wilhelmine zu Leiningen, Gräfin zu Solms-Laubach-Wildensfels, Leiningen family, Solms-Laubach-Wildensfels family, Countess, German, bouffant curly coiffure, hat, coat, collar, lapels, epaulettes, long close sleeves, buttons, cuffs, natural waistline, lining, bodice, vee neckline, neckline ruff, close skirt, flounces