Ellen warned Cathy not to show her friendship with Hareton too much in front of Heathcliff, but she could care less about being afraid of Heathcliff. Hareton was till timid in front of Heathcliff, though, but at least he wouldn’t hurt Cathy for him anymore.
Hareton asked Cathy not to bad-mouth Heathcliff anymore because despite everything he was a father figure to him. She wouldn’t like it either if Hareton bad-mouthed Edgar right in front of her. Cathy agreed.
The more Heathcliff looked, the more he saw Catherine in both Hareton and Cathy, and as if he felt he was going to die soon, he began to act weird.