Dorothy Cayley was the daughter of Sir William Cayley, 2nd Bt. and Mary Holbech. She was baptised at All Saints, Brompton by Sawdon, Yorkshire on 15 December 1664. She married Sir John Legard, 2nd Bt., son of Sir John Legard, 1st Bt. and Frances Widdrington, in 1695. She died on 11 July 1739.