What is it about Mrs. Plum that confuses Karabo in the novel, Mrs. Plum?

Mrs. Plum is a member of South Africa's privileged white minority but also an author and activist campaigning for better treatment for the black majority. Mrs. Plum entertains whites and blacks in her home and goes to jail rather than have her black servants searched under the conditions of the pass laws but is adamantly opposed to her daughter marrying a black doctor whom Mrs. Plum invited to several dinner parties. She forces Karabo to eat at the table with her but does not try to learn about the food Karabo likes. She tries to help Karabo improve herself by offering her reading material and paying for dancing lessons, but she can be petty as an employer and refuses Karabo a few days off to mourn her uncle's death. Mrs. Plum is typical of the white liberal in South Africa under apartheid: she likes the Africans as a people but does not try to know them as individuals.