What is the way to deal with a husband's mother who oversteps her bounds with insults and accusations, and incites her son to mistreat his wife and prevent her from communicating with her family, which affects the marital relationship?

If the mother-in-law's conduct, involving insults and causing discord between the spouses, harms the wife, then this is a reprehensible and forbidden act. It is not permissible for the husband to condone his mother's actions; rather, he must enjoin her from the evil and defend his wife, because obedience to the mother is only in what is good. Similarly, her obedience is not obligatory in preventing the wife from visiting her family, and the husband must provide his wife with an independent dwelling if shared accommodation is a cause of problems. Piety and striving for reconciliation are recommended.