1749 Marie Josèphe de Saxe, dauphine by Maurice Quentin de La Tour (Gemäldegalerie Alte Meister - Dresen Germany)
From Wikimedia.
You saw the print - here is the de La Tour original with lace neck band and jabot and gold lace revers.
Keywords: 1749, de La Tour, Marie-Josephe de Saxe, Wettin family, Bourbon family, Princess, French, straight coiffure, cap, bows, high neckline, neck ruff, lace, jabot, revers, ruching, square neckline, bows en échelle, three quarter length close sleeves, engageantes, lace, order bows