By no measure does Asad Khan looks 20. Unless he was born before they got married which does not appear to be the case. Also this implies that Rashid was married to both Dilshad and Shirin at the same time as he has daughters of the same age. And as they are in college, the girl who is getting married must be at least 19 if not 20. And the convo from yesterday separates Asad and his sister from each other by an age difference of at least 4-5 years. Thus, it must be that Rashid must have married Dilshad at least 25-27 years before to have fathered Asad and then Najma and while at it, met Shirin (the crazy, silly girl) and in the process of "helping her" would have been forced to marry her and set up family with her.