Dorothy Grace Lee attended the Girls' High School, Sea Point, Cape Town, and passed the matriculation examination of the University of the Cape of Good Hope in 1907. She continued her studies at the South African College, Cape Town, and was awarded the degree Bachelor of Arts (BA) with honours in botany by the University of the Cape of Good Hope in 1910. She stayed on at the College to 1912 and in that year published "Notes on the anatomy and morphology of Pachypodium namaquanum" in the Annals of Botany (1912, Vol.26, pp. 929-942).
From about 1914 to at least 1916 Lee was a teacher at the Girls' High School in Worcester. She married Jacobus Francois van der Westhuizen in Cape Town on 27 June 1918.