Margaret was the daughter of William Tinneny and Mary Ellen McShane of Belturbet, County Cavan, Ireland; granddaughter of Robert Tinneny and Bridget Rooney of Belturbet; great-granddaughter of Francis Tinneny and Anne Elliott of Belturbet and great-great-granddaughter of Thomas Tinneny of Goladuff, Newtownbutler, County Fermanagh, Northern Ireland.