Who is Kristina from The Emigrants: A Novel and what is their importance?

Kristina is from a farming family in Duvemala. She is described as tall and child like. Kristina is related to Danjel Andreasson, who is a close relative of Ake Svenson, the founder of the Akian faith. Over the course of the novel, Kristina becomes Karl's wife, and the couple goes onto have four children. She is a loving, faithful, wife and mother, and she supports her husband fully.