Lady Isabella Erskine (1734-1824), the sitter, was the second daughter of Henry 10th Earl of Buchan (and sister of the famous Lord Erskine?). In 1770 she married William Leslie Hamilton, attorney-general of the Leeward Isalnds, who died in 1780. She married secondly, in 1785, Hon. and Rev. John Cunningham, later 1st Earl of Glencairn. Ward and Roberts (Romney, 1904, II p.69) record two whole lengths of this sitter. One of these may be the full-length at Parham House. A half-length portrait is recorded as formerly belonging to Henry Phipps, New York.