Who is Netsai from Nervous Conditions and what is their importance?

Netsai is Tambu's younger sister. On those occasions when the men leave the fields headed for home while the women continue to work, Netsai works as fast as she can to avoid her mother's wrath. Tambu says that Netsai would easily have outworked Tambu, except for Tambu's determination that her younger sister not do so. Tambu notes that Nhamo sends Netsai to fetch his luggage on his rare visits home, and that Netsai doesn't mind running the errand and only asks Tambu for help if there is too much to carry. Sometimes, she even straps their youngest sister, Rambanai, to her back to run the errand.