What are the limits of how a mother should be treated, and how should she be guided and dealt with if she errs, especially if she interferes in her children's lives, mistreats their wives, and cuts ties with her children without clear reason?

A mother has no right to interfere in the lives of her married children except through good counsel. It is not permissible for her to insult her sons' wives. However, this does not justify her children mistreating her or failing in their duties towards her, for honoring one's mother is among the most obligatory duties, regardless of her condition. The children are advised to honor their mother, care for her, obey her in what is good, avoid displeasing her, show affection and concern for her, and deal with her wisely to combine honoring her with treating their wives well through placating and using indirect speech and veiled expressions. Furthermore, soft speech and responding to evil with good bring affection and ward off the evil of Satan, in accordance with the Almighty's saying: "Nor can goodness and evil be equal. Repel (evil) with that which is better; then verily he, between whom and you was enmity, (will become) as though he was a close friend." (Qur'an 41:34) Enjoining the mother to good and forbidding her from evil should be done gently and respectfully. It is not permissible to scold her or speak harshly to her.