Her article in thepeerage is here.
From the Christie's Web site.
Lady Charlotte's dress has most of the ingredients of Napoléonic dress, possibly including a constructed bodice, in this 1802 Hoppner portrait.
Keywords: 1802, Hoppner, Charlotte Keppel, Charlotte Foote, Keppel family, Foote family, British, long straight coiffure, ribbon headdress, neck band, fichu, chemise, modesty piece, bodice, square neckline, long upper puffed sleeves, waist band, Empire waistline, close skirt, wrap