An influential practitioner and educator, Wisnicki was also the first woman to graduate from the School of Architecture at McGill University in 1943.

In her early years of practice, Wisnicki worked with A.J.C. Paine and Lawson & Betts. She also participated in the planning of Arvida, Québec, for the Aluminum Company of Canada. Immediately following World War II she was employed by the Canadian Wooden Aircraft Company in Toronto to undertake a study of prefabricated housing. Wisnicki became an expert in the subject of "prefab" construction, co-authoring a major article on the subject with city planner E.G. Faludi in 1945.

That same year, she registered with the Ontario Association of Architects, becoming their fourth woman member. In 1946, she was the second woman to register with the Architectural Institute of British Columbia. Most of her career, in fact, was spent with the Vancouver firm Sharp, Thompson, Berwick & Pratt (see Thomp​son, Berwick, Pratt and Partners). There she worked closely with Ned Pratt, participating in the design of the Brooks, Saba, Gregg and Mathers residences, all considered icons of Canadian Modernism.

With John Porter, she designed the Daniels and Nemetz houses. Wisnicki, Porter and other McGill alumni were important purveyors of Modernist ideas to the West Coast in the immediate postwar period. They contributed to the development of the regional style known as BC Modernism, characterized by a frank expression of structure, inspired by the BC landscape, climate and relaxed lifestyle.

In 1963, Wisnicki began teaching part-time at the School of Architecture at the University of British Columbia. She joined the faculty full-time in 1969 and retired in 1986. In 1996, Wisnicki received an Honorary Doctorate of Science from McGill University to mark her contributions to the profession of architecture in Canada.