Summerskill appears in a specially selected list of Fabian Society members from 1942 to 1947, showing continuity and prestige. An active feminist, she was instrumental in promoting women's causes throughout that period, starting with the Clean Milk Act in 1949. Later, as the president of the Married Women's Association, she campaigned in and outside the parliament to assure the equal rights of housewives and of divorced women, which resulted in the Married Women's Properties Act in 1964 and the Matrimonial Homes Act in 1967.