Why is Aaliya afraid of her half-brother, The Eldest, in the novel, An Unnecessary Woman?

Aaliya admits to being frightened of her half brother, as she feels as if he always wants to fight and argue with her. She also remembers that when her husband had first divorced her, he had been the one who’d most wanted Aaliya’s apartment for himself. The Eldest was among those who had banged on her door and yelled at her because he wanted her to give him her larger apartment.