Ann Katharine Mitchell (née Williamson; 19 November 1922 – 11 May 2020) was a British cryptanalyst and psychologist who worked on decrypting messages encoded in the German Enigma cypher at Bletchley Park during the Second World War.
[1] Herbert had previously worked in the Indian Civil Service; Winifred had helped organise one of the first family planning clinics in Britain.
[6] Much of her work involved converting 'cribs' into 'menus', the operating instructions for the Bombe decryption devices, to identify what that day's Enigma settings might be.
[10] Once the work at Bletchley became public and the ban was lifted she gave many illustrated talks and interviews about her wartime role.
Scott concluded that "Mitchell has had a profound influence on family law in Scotland",[18] and that her 1985 book Children in the Middle was "a seminal work" in the field.
He died on 26 February 2018, having retired as a senior civil servant in 1984, after which Ann and he worked for many years in the voluntary sector and academia.