Who is Firdaus' Uncle from Woman at Point Zero and what is their importance?

Firdaus' uncle is much older than she is, and he attends classes at El Azhar in Cairo. He teaches Firdaus the alphabet, and she begs to go with him when he returns to Cairo. He also touches Firdaus under her galabeya while she kneads dough, but she feels no pleasure. Firdaus' uncle sends her to school when her father dies, and after her mother dies, he takes her to live with him in Cairo. Firdaus is closer to her uncle than her father, and though she wants to tell him she loves him, she is unable. When he marries a cold woman, he sends Firdaus to the boarding section of her school, and after Firdaus receives her secondary school certificate, her uncle agrees to marry her to Sheikh Mahmoud.