The daughter in law does not care too much about her mother in law's picky attitude. They do not fight. Maybe she does care. That is why she usually does not stay at home. Sometimes she does not go back home to sleep.
The son needs his parents to take care of the family. Also he is very Xiaoshun. He joins her mother to be picky to his wife. And this causes the grand-daughter in the family is picky to her mother now.
You have to admit sometimes even if people make a lot of money they still do not want to spend 40K for parents to live outside. For this family, they have father in law too. So two people will be more than 40K. And the parents have house and good pension in China. They do not want to go back too. They just want to live in a hard life together in Canada.
And the point I am trying to make is when mother in laws complain, it might not all the daughter in laws fault. So it does not matter what kind of currency the family is making. In China and in Canada, it is all the same. You cannot blame a daughter-in-law just because her mother-in-law said she was not Xiaoshun.