Is the wife sinful if she expresses her opinion on immodest clothing (such as evening dresses and trousers) to their wearers or her relatives by saying: "This is beautiful" or "This is good," and what should she do in such situations?

If a wife knows, or strongly suspects, that clothes will be used in an act of disobedience, such as for immodest display (tabarruj), then it is not permissible for her to praise them or express an opinion that encourages their purchase. Instead, she must denounce anyone who wishes to buy and use them in an unlawful manner. She should explain the impermissibility of such an act and not assist in their purchase by praising or commending them.