Chapman was born in England on 6 May 1907 and immigrated to Canada in 1918.   She received a Bachelor and Master's degree from the University of British Columbia in commerce and was later a member of the Montreal wing of theCanadian Civil Liberties Union. Chapman was working for the Bank of Canada when she was detained by the RCMP in 1946.  She played a relatively minor role in the conspiracy but had connections to almost everyone detained by the commission.  She is also notable for having consistently aroused the ire of the commissioners by always evading  their questions.  Chapman was later acquitted in court.

"For many, the trauma and humiliation were difficult to bear. This was particularly true for Chapman, a talented and successful young economist who had received a master's degree from the University of Toronto and was working at the Bureau of Dominion Statistics. Her name did not come up in the Gouzenko documents, but she knew several of the accused spies, who participated in Marxist study groups held at her home on Somerset Street in Ottawa, just a few blocks from where the Gouzenkos lived. In her testimony before the Royal Commission, Kathleen Willisher, who belonged to one of the study groups, claimed Chapman was a secret GRU contact, so the RCMP arrested her. Despite her eventual acquittal, Chapman lost her job, and the publicity was such that she felt compelled to leave Canada for several years. In the early 1960s, she took her own life." [Source: Amy Knight, How the Cold War Began: The Gouzenko Affair and the Hunt for Soviet Spies (Toronto: McClelland and Stewart, 2005), 184.]