[4] Between 1895 and 1899, Knowles was one of the London School of Economic's first research students and taught there as an occasional lecturer between 1897 and 1898.

[5][6] In 1904 she gained a teachership in modern economic history at LSE — thus, according to Berg, "becoming the first full-time teacher of the subject at any British university".

[3][6] Knowles campaigned vigorously on behalf of pacifist students and colleagues during World War I.

[7] In 1921, Knowles was promoted to a professorship in Economic History becoming Britain's second professor in that subject (the first being George Unwin at the University of Manchester).

[3] Outside academia, she was appointed by Bonar Law to a government inquiry into working class cost of living, and was the only female member of the Royal Commission on Income Tax, 1919–1920.