The sitter was the eldest daughter of John Palmer of Torrington and his wife Mary. She was the niece of Sir Joshua Reynolds and the chief beneficiary of his will. She was an amateur painter and miniaturist and she made a number of copies of Reynolds's paintings. A self-portrait is in the Fitzwilliam Museum, Cambridge (inv. no. 3763). She married, as his second wife, Murrough O'Brien, 1st Marquess of Thomond, an Irish peer, soldier and politician. For a fuller account of the sitter's life see The Hon. D. O'Brien, Miniatures in the XVIIIth and XIXth Centuries, London, 1951, pp. 107-113.