The daughter of John Nelthorpe and Mary Cracroft; in 1799 she married William Beauclerk, eighth Duke of St. Albans.

CORRESPONDENCE OF Maria Janetta Beauclerk, duchess of St. Albans [née Nelthorpe]:

Samuel Rogers to Maria Beauclerk, Duchess of St. Albans, [1813] in Samuel Rogers and his Contemporaries 2 Vols (London: Smith, Elder & Co., 1889)