Is it permissible to complain about the wife's mother who insults the husband and his family and mentions his private matters, after speaking with her guardian who did not stop her?

Responding to ill-treatment with kindness is among the most perfect virtues for a believer, for it carries immense reward, transforms animosity into affection, and brings Allah's support and assistance.

The wronged person has three options: forgiveness and overlooking; or refraining from forgiveness; or retribution equivalent to the offense. Forgiveness and overlooking are considered the highest and best of these stations.

Therefore, it is advisable to forgive and overlook the mother-in-law, while gently and kindly attempting to advise her. If her insults persist and her guardian does not restrain her, then there is no blame in complaining about her to official authorities or to someone who has the ability to render justice to the wronged.