When is jealousy blameworthy or praiseworthy, and is jealousy over one's fiancée for revealing her face to non-mahram relatives (such as paternal or maternal cousins)—bearing in mind that they live in one house, but each family has a private apartment—considered blameworthy jealousy?

Jealousy (ghirah) concerning the sacred limits of Allah is a religiously commanded trait, and it is among the characteristics of the people of faith. This is based on the Prophet's (peace be upon him) saying: "Indeed, Allah feels ghira, and the believer feels ghira, and Allah's ghira is when a believer commits that which He has forbidden him." It is not permissible for a woman to uncover her face in front of a non-mahram (definition) man, because covering it is a religious obligation according to the preponderant opinion. The presence of everyone in one house does not permit her to uncover it.