Rebecca Sieff (1890–1966) her father was Michael Marks (1864–1907).
"Rebecca was the second of her parents’ five children—Simon (1888–1964) married Miriam Sieff, Miriam (1892–1975) married Harry Sacher, Mathilda (1895–1964) and Elaine (1902–1985)... During Sieff’s school days the movement for women’s education was spreading. One of its aims was to make higher education available to women; Manchester University was part of this movement. In possession of a high school diploma, Sieff enrolled in the women’s section of the university, where she majored in English literature. At that time her future husband, Israel Sieff, was studying economics at the university; in 1910 they were married...
"Prior to the outbreak of World War I, a number of women’s groups were established within the Zionist movement; one of them was B’not Zion, of which Sieff was a member. During the war Sieff collected funds for the Charity Fund for Polish Jewry and was among the founders of the Rehabilitation and Preparation Fund, a precursor of Keren Hayesod (founded in London in 1920). In 1918 Sieff was one of three women members of the Zionist Federation of Great Britain who were elected in their own right to the Council of the English Zionist Federation, rather than as representatives of certain women’s groups connected to the general Zionist Federation. The others were Romana Goodman and Vera Weizmann.
"In 1918 women members of the Zionist Organization of England were enabled to set up their own organization, the Federation of Women Zionists (FWZ) in England and Ireland... In April 1918, with the support of the British government, the Zionist Commission under the leadership of Chaim Weizmann arrived in Palestine; the other seven members represented the wartime allies and included David Eder and Israel Sieff. The committee’s mandate was to study the general situation in Palestine and prepare a recommendation to the British government of ways to apply the Balfour Declaration..." In 1926 Rebecca and Israel Sieff and their four children Michael Sieff (1911–1988), Marcus Sieff (1913–2001), Daniel Sieff (1915–1932) and Judith (1921–1994) moved from Manchester to London. "Sieff continued to serve as president of WIZO (1920–1966) and devoted the main thrust of her energies to projects for women’s agricultural training; she continued, moreover, to support the establishment of crêches and other schemes for women’s vocational training..." 
Resources and articles
- JWA Rebecca Sieff, organizational web page, accessed May 11, 2012.