Katherine Bigham 12th Lady Nairne, eldest child of Henry Petty-Fitzmaurice, 6th Marquess of Lansdowne (1912-1995) (1912–1995) Parents Henry William Edmund Petty-Fitzmaurice, 6th Marquess of Lansdowne Elizabeth Caroline Hope Children Andrew Bigham David Bigham Richard Bigham, 4th Viscount Mersey Siblings Lord Edward Norman Petty-FitzMaurice Lady Elizabeth Mary Petty-FitzMaurice Charles Hope Petty-Fitzmaurice, 7th Marquess of Lansdowne Henry Maurice John Petty-FitzMaurice, Earl of Kerry Partners Edward Bigham, 3rd Viscount Mersey