Is it permissible to give zakat on wealth to the husband's sister whose husband earns enough to provide life's necessities, but she wishes to improve her standard of living (such as enrolling her children in expensive private schools and buying expensive furniture for her children's room)? And is it obligatory for the brother or grandfather to spend on that? And is it permissible to pay zakat to settle her deceased husband's debt, which is an interest-based loan?

He who does not have enough to cover his needs and the needs of his dependents is eligible to receive zakat, even if he possesses some wealth. He who has enough for his needs is not eligible to receive zakat, and seeking expansion or emulating the wealthy is not considered a need. It is not permissible to spend zakat on study expenses unless the students and their dependents are unable to pay them, on condition that the students are intelligent and cannot combine study with work, and that the knowledge they are acquiring is needed by Muslims. It is permissible to pay the father-in-law's debt from zakat if he did not leave behind what would cover his debt, and paying the debt of the deceased takes precedence over paying the debt of the living. This includes only the principal amount, not usurious interest.