Krog grew up on a farm, attending primary and secondary school in Kroonstad. In 1973 she earned a BA (Hons) degree in English from the University of the Orange Free State, and an MA in Afrikaans from the University of Pretoria in 1976. With a teaching diploma from the University of South Africa (UNISA) she would lecture at a segregated teacher’s training college for black South Africans. She is married to architect John Samuel and has four children: Andries, Susan, Philip, and Willem. In 2004 she joined the Arts faculty of the University of the Western Cape.