Nettie travels to Africa after meeting two missionaries, Samuel and Corinne. The missionaries have adopted Celie's two children, Olivia and Adam, and Nettie comes to stay with the missionaries and look after the children, who she at first does not realize are her niece and nephew. At first, another missionary was to accompany Samuel and Corinne on the trip, but when that person married and her husband refused to allow her to go, Nettie was a natural choice to take her place.

Nettie's experiences in Africa provide an important contrast to Celie's experiences. Nettie's life with the missionaries and among the Olinka people in Africa is satisfying in ways that Celie's can never be. Even so, Nettie still is subject to many of the same jealousies that shape Celie's life. For instance, Corrine grows jealous of Nettie's closeness to the children and the way the Olinka have of assuming that Nettie is Samuel's second wife. She becomes convinced that the children are Nettie's biological children and that Nettie and Samuel had an affair before Corrine was married. This jealousy poisons the relationship of the two women, but Corrine's instincts, while wrong in fact, are true in spirit. After Corrine becomes sick and dies in Africa, Samuel and Nettie marry.