Wife’s duty towards her family after marriage

Salaam,Does a womans duty to her family end or lessen after she gets married? My sister got married about 2 years ago. My family was excited at first, but now after two years the attitude is basically, ?She?s married now, we?ve lost her?.I?ve often noticed that when a conflict arises between a woman and her in-laws, the imam and scholars will often say that it is haram to make a man choose between his mother and wife. They will often stress the fact that it is the wife has a responsibility toward her in-laws. Why is the same advise not given to the man when he and his father-in-law are in conflict?I swear to god when I say this, but at 30 yrs old, I have never heard an imam or scholar say that a man must respect his wife?s family. In fact many men will verbally abuse their wife by cursing and insulting her family. They do this quite mercilessly. On the other hand if the wife were to say something, the results are often disastrous.In the case of a conflict between the husband and father, the woman is often told to side with the husband, effectively pitting one party against the other. Why is the woman never told to try to find a balance, like the man is told too. Is she no longer a daughter? To add to the insult the man is often told to ?relax? in this area so that his wife can see her family, as it is some sort of privilege that the husband may give his wife if she is ?obedient?.I know that it is a grave sin for a woman to insult her husbands parents and to break ties with them, but does this also apply to the husband and his wifes family? Is the sin of bad behavior toward the husbands family equivalent to the sin of bad behavior to the wife?s family? In other words is it worse to insult the husbands family than the wifes family? Does the bad behavior towards the wifes family even classify as a sin?I?ve often been told that we shouldn?t question Islam because we cannot question Allah. I hate to say this, but I cannot understand why this behavior is accepted. I tried to tolerate it at first but as of recently I cannot help but question.