She founded a Mental Welfare Association in her home town of Paisley in 1907, which was the model for the Scottish Association for Mental Health (1920), on whose board she was a long serving member. She became in 1914 the first woman Deputy Commissioner on the General Board of Control for Scotland, after the Mental Deficiency Act of 1913 permitted the inclusion of women in that body, and she became a full Commissioner in 1935. She emphasised the importance of the relationship between the mentally ill and the community in all her work.
Fraser specialised in child psychology and in 1908 was the first woman School Medical Officer for Govan. Following on her research work in Vienna and Paris, she pioneered the use of Binet-Simon intelligence tests in the United Kingdom with her research into syphilis related mental deficiency in Glasgow in 1913.
She retired from her role as Commissioner of the General Board of Control for Scotland in 1947 and took up a new position as chair of the Scottish Association for Mental Health.