"Elector Maria Anna of Bavaria, née Princess of Saxony, at the piano", Georg Desmarées
So-called portrait of maria anna sophia of saxony (1728-1797), but is probably a depiction of countess palatine maria franziska of sulzbach (1724-1794)
identification proposed by user ecummenic (talk) based on the comparison with some portraits of maria franziska of sulzbach (see images below) and the lack of physical resemblance with maria anna sophia of saxony. Date: 18th century. Medium: painting. Collection: Unidentified location. Georg Desmarées - So-called portrait of Maria Anna of Saxony, Electress of Bavaria