Who is Sharifa Salah el Dine from Woman at Point Zero and what is their importance?

Sharifa Salah el Dine is an attractive woman who approaches Firdaus on a bench facing the river after Firdaus escapes from Bayoumi. She takes Firdaus home where she bathes and dresses her. Sharifa tells Firdaus that she must value herself highly so that men know her worth. When she refuses to let Fawzy take Firdaus, he rapes and beats her.