Ruth May's getting worse, but Tata Ndu has been surprisingly generous to the Price family.
Nelson tells Mother that Tata Ndu been showering them with gifts because he wants to marry Rachel. Seeing what a ridiculous match this would be, she can't help laughing.
Nelson says Tata Ndu wants Rachel because she's white, a different color from all his other wives.
Mother doesn't understand, thinking that this makes Rachel sound like an accessory.
Then they just stare dumbly at each other. Adah observes, "My mother and Nelson had reached the limits of mutual understanding" (3.9.32).