How does Okonkwo treat his "most senior" wife? What does it demonstrate about the role of gender within the Ibo community?

Ikemefuna is valued by Okonkwo and even loved. When Okonkwo has to leave he puts the boy in the care of his "senior" wife. She is treated with more respect than the others because of her place, but as far as gender roles.......... he ORDERS her to take the boy.