Nettie describes Corrine's burial, which took place in the Olinka way. Nettie also says that Olivia has gotten her first period, and that Olivia and Tashi (who is also now a woman) take care of one another in their new womanhood.
Even as Corrine dies Olivia emerges into womanhood. And Olivia and Tashi's relationship offers an alternative to the jealousy Corrine felt toward Nettie. Olivia and Tashi share a relationship of helping and supporting each other.
Although Corrine was angry with Nettie for many years, fearing that she was the children's true mother, Nettie still believes she ought to forgive Corrine, who died a terrible death, and finally believed Samuel and Nettie upon her deathbed.
It would be understandable for Nettie to remain angry at Corrine, since Corrine did make life difficult for Nettie and for Samuel. But Nettie tries her best to approach the question in a Christian manner—to ask forgiveness of God on Corrine's behalf.
Nettie ends the letter to Celie hoping that the Olinka can somehow preserve their land in the face of the English rubber company's incursion. But Nettie is rapidly losing hope in the village's ability to withstand this onslaught of Western "culture" in the village.
Nettie seems, here, to realize the inexorability of change in the Olinka village. If it isn't the road—which would be hard to stop regardless—it will be something else. The Olinka will be overrun by the strength of the forces of Western "development" and change.