Constance Mainwaring-Burton is a descendant of King Charles II and Moll Davies through the Jacobite 3rd Earl of Derwentwater (see Anya Seton's novel Devil Water):
Charles II & Moll Davies
Lady Mary Tudor (1673-1726), m.(1) Edward Radcliffe, 2nd Earl of Derwentwater
James Radcliffe, 3rd Earl of Derwentwater (executed 1716), m Anna Maria Webb
Lady Anna Maria Barbara Radcliffe (1716-60), m 8th Baron Petre
Katherine Anne Petre (1736-83), m George Fieschi Heneage
George Robert Heneage (1768-1833), m Frances Anne Ainslie
Frances Anne Heneage (1804), m. Edward Giles Howard of the dukes of Norfolk family
Adelaide Laura Howard (1839-1916), m Sir Frederick Marshall
Sybil Mary Marshall (1868-1933), m 3rd Baron Burnham
Margery Olive Edith Lawson (d 1969), m John Fenwick Harrison
Penelope Anne Harrison (1926), m John Roland Christopher Riley
Bridget Mary Riley (1958), m Guy Anthony Mainwaring-Burton
Constance Elizabeth Mainwaring-Burton, b. 1989