ca. 1773 (estimate based on coiffure) Marie Clotilde of France (Madame Clotilde) with a guitar after François Hubert Drouais (location unknown to gogm)
She was the younger sister of Louis XVI and became Queen of Sardinia. Her husband Carlo Emmanuelle's younger sister Marie Joséphine became Comtesse de Provence and later Queen of France while his sister Marie Thérèse became Comtesse d'Artois as part of the arrangements that included Madame Clothilde's marriage.
From the 2.bp.blogspot.