Her article in thepeerage is here.
From www.artscroll.ru/page.php?al=John_Hoppner_hudozhnik; size doubled by gogm.
Lady Louisa makes her first appearance in British casual day dress with something spilling out of the décolletage of what appears to be a criss-cross bodice. She wears a large coiffure typical of the late 1770s - without powder.
Keywords: 1779, Reynolds, Lady Louisa Manners, Tollemache family, Manners family, Countess, British, high straight coiffure, scoop décolletage, modesty piece, criss-cross bodice, elbow length sleeves, waist band, full skirt, coat, elbow length notched over-sleeves, shoes