In May 1920, Algernon Lee, educational director, presided over the graduation of the second-largest class ever at Rand, whose members included: John J. Bardsley, William D. Bavelaar, Annie S. Buller, Louis Cohan, Harry A. Durlauf, Clara Friedman, Rebecca Goldberg, William Greenspoon, Isabella E. Hall, Ammon A. Hennsey (Ammon Hennacy), Hedwig Holmes, Annie Kronhardt, Anna P. Lee, Victoria Levinson, Elsie Lindenberg, Selma Melms, Hyman Neback, Bertha Ruvinsky, Celia Samorodin, Mae Schiff, Esther T. Shemitz, Nathan S. Spivak, Esther Silverman, Sophia Ruderman, and Clara Walters.

[1][3][4] While at Rand, Buller helped raise funds in New York for Canadians in the Winnipeg General Strike.

The start-up committee comprised: Buller, Becky Buhay, Becky's brother Mike Buhay, Bella Gauld, a Mrs. Frankel, Mike Garber of the Revolutionary Communist Party of Canada (CPR), Nathan Mendelssohn, George Lloyd, Dick Kerrigan, Bill Long, and Sylvia Robertson.

[4] Following the 1931 Estevan Coal Miners Strike, Buller spoke in support of formation of the Mine Workers' Union of Canada.

During the later 1930s, she managed the Mid-West Clarion party newspaper of Winnipeg until its repression under the War Measures Act (Defence of Canada Regulations).

In 1940, during a crackdown on Communist Party members, Buller was arrested along with Louis Guberman and Jock McNeil and jailed in Portage la Prairie (1940–1942).

After World War II, Buller continued to be involved in CPC activities such as the campaigns to roll back prices organized by National Women's Commission and the Housewives' Association.

[7] p. {{{1}}} Buller married Harry Guralnick (died 1972), who was an activist in the Jewish Labor League; they had one son, Jimmy.

[1] CPC member John Weir called Buller Canada's Rosa Luxemburg and Elizabeth Gurley Flynn.