What is the main conflict in Nervous Conditions by Tsitsi Dangarembga?

Set in white-dominated Rhodesia of the 1960's, Tambu begins her story by talking about her brother's trip to and from mission school each day. She says that he complains about the trip - especially the two-mile walk from the bus station to their home - and that she could talk endlessly about all there was to do during that walk and how much she loved it. Children, including Tambu, were seldom restricted and were allowed to swim in the pools.