Harriet Lydia Montagu (daughter of the 6th Baron Rokeby, Major-General commanding the Brigade of Guards).
Together, they were the parents of:[5] Lord Portarlington died of "congestion of the kidneys" at the Royal Palace Hotel at Ostend, on 31 August 1900 at age 42.
Mary FitzWilliam (daughter of William Charles Wentworth-FitzWilliam, Viscount Milton), on 25 September 1901.
[5] Through her daughter Lady Aline, she was a grandmother of Celia Marjorie Vivian, who married Sir John Molesworth-St Aubyn, 14th Baronet, eldest son of Sir Hugh Molesworth-St Aubyn, 13th Baronet.
[5] Through her daughter Lady Christian, she was a grandmother of Rosemary Lusia Bowes-Lyon (1915–1989), a first cousin of Queen Elizabeth II who married Edward Wilfred George Joicey-Cecil, youngest son of Col. Lord John Joicey-Cecil, MP for Stamford (a son of the 3rd Marquess of Exeter), in 1945.