Lecha and Zeta in this novel are two twin sisters, who have been selected by the spirits to fulfil specific roles in the struggle to reclaim the land. They are both meant to be mother figures for the indigenous people, and Zeta is mean to be the physical mother and Lecha the spiritual mother. It is their grandmother, Yoeme, who tells them about their special identity and gives them the task of transcribing the stories into the Alamanac. She also makes it clear that they must help each other and support each other throughout their life as they work on this viatal task together.
This helps to explain the very close relationship that the twins enjoy throughout their lives. Although they have times of separation and disagreement, there is a core connection that sustains their relationship and keeps them together in spite of the forces that threaten to disrupt their unity. Remember that during their so called "coyote years," where the two girls have many different jobs and do many different things, Lecha has a child but leaves him for Zeta to raise at the ranch, showing how much she trusts and cares for her. Again and again, in spite of the struggles that they endure, the connection that was forged at their birth is shown to be sustained.