Darwin was appointed to the Board of Control, as an unpaid member, in 1921, replacing Ellen Pinsent.[3] She retired from the Board of Control in 1949.[4]
In 1929, with money from the estate of her father who had died in 1928, she founded the Darwin Trust[5] to foster research into "mental defect, disease or disorder".[6]
In 1948, she married the Welsh psychiatrist William Rees-Thomas, who was a colleague of hers on the Board of Control.[10] She died in 1972, predeceasing her husband.[11]
^‘DARWIN, Ruth Frances’, Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2008; online edn, Oxford University Press, Dec 2007 accessed 27 Dec 2012
^The Times, Tuesday, 19 April 1921; pg. 4; Issue 42698; col F
^The Times, Thursday, 15 September 1949; pg. 7; Issue 51487; col D
^‘REES-THOMAS, William’, Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2008; online edn, Oxford University Press, Dec 2007 accessed 27 Dec 2012
^Obituary: Mrs W. Rees-Thomas, The Times, Monday, 16 October 1972; pg. 14; Issue 58606; col F