Melancholy, Constance Marie Charpentier
On Wikimedia Commons; original is in the Musée de Picardie, Amiens, France.
Charpentier is another of those fine French painters from the 18th and 19th centuries about whom we know little, likely because they were female — even though Charpentier won gold and silver medals in the Pais Salons of 1814 and 1821.
Charpentier is thought to have been a student of Jacques-Louis David, though that has not been established with certainty. Some of her works were at one time attributed to him.
On a side note: a wonderful painting in the Metropolitan Museum of Art titled Young Woman Drawing, also long incorrectly attributed to David, was at one point attributed to Charpentier, before its current attribution was established to another skilled female French artist for whom there is little information available, Marie-Denise Villers.