 After obtaining her diploma from Exeter, Sanderson taught at a girls' school in High Wycombe, then in 1951 accepted a post in Egypt to teach at the English Girls' College in Alexandria.From 1953 she taught at Omdurman Girls' Secondary School in Omdurman, Sudan, and from 1954 to 1958 served as headmistress of Omdurman Intermediate School.From then until 1962, she was headmistress at Khartoum Girls' Secondary School; she wrote that the school represented "the greatest single development in government secondary education for girls in the Sudan".