After a period as a custodian at Thorvaldsens Museum, with her appointment as history of art professor at Aarhus University in 1954, she became the third woman in Denmark to hold a professorship.
Over the following 25 years she was a key figure in the development of the history of art as a modern academic discipline, becoming a professor at the University of Copenhagen in 1967.
In March 1934, she married the painter Kai Louis Sass (1898–1957) with whom she had three children: Lotte (1934), Pernille (1938) and Karsten (1941).
During her 25 years of professorship in Aarhus and Copenhagen, she developed history of art as a modern academic discipline backed by the highly qualified staff she brought in.
[3] Among Sass's publications are the three-volume Thorvaldsens Portrætbuster (1963–65) and a new edition of Kunstforståelse - maleri (Understanding Art - Painting), published in 1967.