Jenny is really immature, regardless of her age. She and Summit went into the counseling with the attitude that the counselor would tell his parents why they were wrong and should totally support the marriage.
It was interesting though, showed a little more maybe about why his parents are so against it. There is the idea that their DILs should take care of them as they age of course. And since Jenny isn't going to be having babies at this point, they are concerned about who will take care of Summit when he gets old. Given their culture, makes some sense.
I agree with the commen