Eshan's mother is playing a perfect "Old Crone." You know, the literary figure who tries to manipulate and destroy the lives of younger people, because she desires power moreso than love? She seems to get some great payoff from being able to move people around like pieces on a chessboard. I wonder if she realizes that the Old Crone is usually left alone and friendless, if not dead?
I don't blame Joss for wishing to end things. How long can love endure, under these circumstances? They would have to move away, or at least stay away from her influence in the community. This would deny Eshan the love, respect and approval of the surrounding community that he has worked so diligently to obtain.
It's interesting that Eshan's mother thinks that she is saving her family from Joss. What if Yaghoub decides to exercise his right to divorce her, instead? He obviously loves his children, and his grandchildren, enough to wish them happy, and he must realize by now that she does not share those values. In addition, how could she shame her entire family this way, before the community, and expect for him to continue to support her actions?
Eshan's sisters have husbands, and if I were them, I would forbid that poisonous woman any contact with my family, including my children. After her threats and actions, she would never again enter my home.
Finally, by denying Eshan his "gift," she has cut off any relationship she hoped to continue to have with him. She may have also done the unthinkable: caused him to question his relationship with Allah. Humans are prone to wonder whether God is real, and whether He is concerned about our suffering, when these types of circumstances arise. Also, the officiant's refusal to perform the ceremony seems to have been a final straw for Joss. Wouldn't it be ironic if Eshan decided to turn from religion and from tradition because that harpy was trying to "save" him from Joss, a woman who was perfectly willing to honor both?
I doubt if the elder Mrs. Kourosh will have a crisis of conscience, but I do encourage you to have her experience Eshan in a crisis of faith, due to her actions. She is trying diligently to preserve the Eshan she knows and approves of, and does not realize that if he loses Joss, that Eshan will be gone forever. He will ever wonder, "Where is the reward for the faithful?" Even if he marries the woman of whom she approves, he will be a shadow of his former self, and have no real joy in her, as she is not his desired wife.
I do hope she realizes the consequences of her actions before it is too late, but in real life, she would probably be too drunk on power to bother with logic.