Mary Grace Lester (1911-1980), political activist, was born on 23 January 1911 in Perth, daughter of Francis Scott, a clerk from Scotland, and his Sydney-born wife Grace Mary, née Turrell. Mary worked in a number of jobs before becoming a typiste. At St Mary's Catholic Cathedral, Perth, on 24 February 1936 she married Bernard Murtough Terry, a 30-year-old clerk. He served as a squadron leader in the Royal Australian Air Force during World War II and was killed in North Africa on 16 November 1942. To provide for their three sons, Mary returned to work. On 27 October 1944 at All Saints Church, Osborne Park, she married with Anglican rites Cecil Lester, a 26-year-old mechanic who had enlisted in the army. She gave birth to a daughter in 1946, but separated from her husband two years later. Mary's father moved in with her to help care for the children while she held a secretarial post at Royal Perth Hospital. Her petition for divorce was to be granted in 1955. In the late 1940s, having campaigned against the Cold War and called for nuclear disarmament, she joined the Communist Party of Australia.
The Western Australian branch (formed 1951) of the Union of Australian Women agitated against nuclear weapons. Lester became its secretary in 1955. In the following year she was appointed vice-president of the U.A.W.'s national committee. The union had links in Perth with the Native Welfare Council, the Combined Equal Pay Committee, the Western Australian Association for Children's Film and Television, and the women's committees of the Seamen's and Waterside Workers' federations. Women marched in Labour Day and May Day processions in that city and at Fremantle. In 1957 Lester joined other U.A.W. members in lunchtime marches on Fridays through the streets of Perth. They wore aprons and scarves, made from flour-sacks or shopping bags, which were inscribed with such slogans as 'Danger! Stop all bomb tests', 'Ban the A-bomb' and 'Mothers Join Us, Protest Too'. Street protests were forbidden under the Western Australia Police Act (1892). On 13 September 1957 five marchers, including Lester, were arrested. They were convicted on 10 October of carrying 'printed notices without permission in a public place'. Their appeal against the fines was upheld by the Supreme Court. The lunchtime marches continued until 6 August 1958, the thirteenth anniversary of the bombing of Hiroshima.
In June that year Lester visited Vienna as a national delegate to the World Congress of Women; she travelled to Moscow before returning home in November. As secretary (1960) of the International Women's Day committee, she invited German, French and Indonesian women activists to speak to U.A.W. members. In 1962 three Soviet women visited Perth for International Women's Day. Lester stood unsuccessfully (1963 and 1964) for election to the Perth Shire Council as a communist candidate.
In poor health, and perhaps sensing that it was time to make room for a younger woman, Lesterresigned as State secretary of the U.A.W. in 1965. She travelled to Libya in 1979 to see the grave of her first husband. Survived by her four children, she died of myocardial infarction on 14 August 1980 in Royal Perth Hospital and was cremated.