The daughter of William Ponsonby, 2nd Earl of Bessborough; in 1770 she married William Fitzwilliam, earl Fitzwilliam.

REFERENCES TO Charlotte Fitzwilliam, countess Fitzwilliam [née Ponsonby]:

Thomas Creevey to Elizabeth Ord, 25 October 1820 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)