What is your advice to me regarding my wife, who discloses our private household matters to her family, despite my repeated warnings to her not to do so?

A wife is not permitted to inform her family or others about the private matters of her husband and home if her husband has forbidden her from doing so, because obedience to him is obligatory in what is good and lawful. If the discussion pertains to intimate marital relations, it is absolutely forbidden for both spouses, due to the Prophet's (peace and blessings be upon him) saying: "Indeed, among the worst people in rank before Allah on the Day of Resurrection is a man who goes to his wife and she goes to him, and then he divulges her secret." The husband should exercise patience and wisdom and seek excuses for her. If her discussion is about general matters not related to intimate relations, then he should not hold her accountable for it.