What's it like to have a reasonable sister-in-law?

I am a sister-in-law. There are six brothers and sisters in our family. It's been almost 30 years. The four of us have never been red-faced with our sister-in-law, and we have always been in harmony. Because growing up, we have seen many contradictions between those sisters-in-law and mother-in-law, and our aunt is also that kind of troublemaker, so I despise those sisters-in-law, from the heart. Of course, both sisters-in-law will bump into their mother when they enter the door. But every time I speak from the standpoint of my sister-in-law, I will send my mother away first and convince my sister-in-law, and then I will quietly clean up my mother. We all criticize my brother and speak for my sister-in-law. We have no food or clothing at home. We'll let my sister-in-law do housework at once. Because our sisters mediate in the middle, there is basically no big contradiction in our family in the first two years of brother-in-law's marriage, unlike other families who call all day.