The elder daughter of Right Honorable Stephen Poyntz of Midgham, Berkshire, Georgiana married John, 1st Earl Spencer and Viscount Althorp on 20 December 1755. They had two daughters and a son: Georgiana, who married William, 5th Duke of Devonshire; Henrietta Frances, who married the 3rd Earl of Bessborough; and George John, who succeeded his father as 2nd Earl Spencer. A portrait of her daughter, Georgiana, Duchess of Devonshire, by Thomas Gainsborough, is now in the NGA (1937.1.93).
Cooper, Douglas, ed. Great Family Collections. New York, 1965:197-240