The previous letter (64) from Nettie was written during the Christmas holiday, and the current letter dates from Easter. Nettie has learned, in the intervening time, that the road is not to stop in the Olinka village, but to continue through it for thirty miles, to the coast. This means that much of the village will be destroyed. After a trip to the coast with Corrine and Samuel, Nettie also learns that the Olinkan land has been purchased by an English rubber company.
Nettie's suspicions were right: the rubber company wasn't building a road to benefit the village. They were building it to benefit themselves, and didn't care if it harmed the village at all. That the rubber company could buy the land without the Olinka even knowing—as if the Olinka, despite living on the land for generations, did not own it themselves—seems shocking and unfair. But it was common practice in Africa at the time of the novel's setting.
The Olinkan chief was forced, after the "sale" of his village's land, to talk to the British "governor" of the region, who told him that the Olinkans must pay rent to the English for their own land, and a water tax as well. Nettie is concerned, and Corrine has fallen ill with "African fever," but the Olinkans in general are so worried about their future, they refuse to act.
The British forcing the Olinkan's to pay rent for their own land echoes Millie's insistence that Sofia thank her even though she messed up Sofia's visit to her family. The powerful white's seem to think it is their right to just take possessions from the weaker black people, and then are astonished when the black people are upset. Corrine's disease is never described, but it might be the same disease experienced by other missionaries who have come to live with the Olinka, and who do not possess the natural immunities required to live in the jungle.
Nettie therefore waits for new developments. In the meantime, Olivia and Tashi continue going to school with the boys—the villagers have tended to accept the fact of Tashi's and Olivia's education, seeing that the missionaries insist upon it.
Tashi and Olivia have succeeded, at least temporarily, in their mission. They are able to sneak in an education as the village is concerned with its own survival.