The Metropolitan Museum has this note about this portrait: "The sitter was one of the great courtesans of her day. Little is known of her early life, but she was presumably born Anne, or Nancy, Parsons, the daughter of a Bond Street tailor. She accompanied a slave trader named Horton, or Houghton, to the West Indies, returning to London as Mrs. Horton. In 1763 she was the mistress of Augustus Henry FitzRoy, third Duke of Grafton, and later, in 1769, of John Frederick Sackville, third Duke of Dorset. In 1776 she married Charles Maynard, second Viscount Maynard, who, at twenty-three, was probably at least a decade younger than she. In 1784 she began an affair with the nineteen-year-old Francis Russell, fifth Duke of Bedford. She is reported to have died in France in the winter of 1814–15.
Waterhouse [Ref. 1973] and Mannings [Ref. 2000] have accepted the identification of the sitter, though the picture is not recorded until its appearance on the art market in 1928, as Nancy Parsons. According to the Bache Collection catalogues [Refs. 1929, 1937, 1943], it had belonged to Frances, Countess of Warwick, granddaughter of the third and last Viscount Maynard. An anonymous, undated print (National Portrait Gallery, London) depicts Nancy Parsons, and she also sat for Gainsborough, but that portrait is lost [see Ellis Waterhouse, Gainsborough, London, 1958, p. 80, no. 475]. The Scottish artist George Willison painted her in Turkish dress (Yale Center for British Art, New Haven), a portrait that was engraved by Ridley as a small oval, in 1771, as Miss P. The present work, like Willison’s, shows the sitter in what an eighteenth-century viewer would have called oriental costume.
According to Mannings [Ref. 2000], Reynolds recorded three appointments for sittings with Mrs. Houghton in 1767 and seven with Mrs. Horton in 1769. A note on technique at the end of the artist’s ledger dates before January 22, 1770, and seems likely, on account of the color scheme, to refer to this picture [see Ref. Baetjer 2009, p. 76 n. 6]."