Katharine (Katie) Julian Bonham Carter,(nee Dawnay), (b. 1968), wife of the actor Crispin Bonham Carter, gave birth to a fourth son, Frank Douglas, 12 January, 2006, a brother for Arthur (b. 1997), Kit (b.?), and Stanley b. 21 Apr 2002. Mrs Bonham Carter is of Royal descent, and is a great-granddaughter of the Hon Hugh Dawnay (1875-1914), (second son of the 8th Viscount Downe), and Hugh's wife the former Lady Susan de la Poer Beresford, daughter of the 5th Marquess of Waterford.
Source: The Times 8 Feb 2006