Marie-Sophie de Courcillon, Duchesse de Pecquigny, Princesse de Rohan (1713-1756) Maurice Quentin de La Tour (1704-1788)

The picture has something of this: people, woman, portrait, wear, man, child, outerwear, indoors, elderly, sadness, music, two, facial expression, retro, sit, son.
Perhaps it’s a portrait of a woman with a blue dress and a blue flower in her hair, holding a sheet of music in her left hand and a book.