Ick, in the promo, Sufiyan tries to get to Ushna before Zainab blocks his way. He has zero boundaries and his antics are no longer just annoying, it's going into scary and dangerous territory. Shehroz's retaliation from the car may have shocked him, because when he hassled Ushna, all she could do was to walk away from him. Shehroz and Wahab are a different story. I guess the same thing applies to Sufiyan's family as well, they expected Zainab to fold easily, but she showed them up.
Zainab is an awesome mom though, after Shehroz complained to her about Sufiyan hanging around Ushna at school, and Ushna explains, she believed her daughter. Zero doubt about her daughter's words to her and there were no accusations or anything.