Katherine married William Cavendish, 3rd.Duke of Devonshire KG PC on 27 Mar 1718. William (son of William Cavendish, 2nd. Duke of Devonshire KG PC and Hon. Rachel Russell) was born on 26 Sep 1698; died on 5 Dec 1755. [Group Sheet]

1. Caroline Cavendish was born on 22 May 1719; died on 20 Jan 1760; was buried in Derby Cathedral, Derbyshire, England.
2. William Cavendish, 4th. Duke of Devonshire KG PC was born on 8 May 1720; died on 2 Oct 1764 in Spa, Holland.
3. Lady Elizabeth Cavendish was born in 1723; died in 1796.