From artuk.org; removed creased paint or substrate flaws in background with Photoshop. Also posted to the Reign of Louis XV - 1715 to 1774 Album here.
Bows and a lace bertha ornament Lady Cust's bodice, but she wears sheer, not lace, cuffs or engageantes. Her sleeves also have folded cuffs in earlier 1700s style.
Keywords: 1748, Hudson, Etheldred Payne, Payne family, Cust family, British, curly coiffure, hair jewelry, fitted bodice, U-neckline, lace bertha, bows, three quarter length full sleeves, cuffs, sheer flared cuffs, full skirt