What should she do concerning the zakat on the gold remaining with her, knowing that she owned 158 grams, sold part of it, paid zakat on another part, and now possesses 90 grams offered for sale, having no money of her own, and her husband is in debt?

Gold prepared for adornment is not subject to Zakat according to the majority of scholars. As for gold not prepared for use, Zakat is obligatory on it if it reaches the nisab (approximately eighty-five grams) and a lunar year has passed over it. The amount of Zakat that must be paid is a quarter of a tenth (2.5%). Zakat must be paid every year upon the completion of the hawl (lunar year), and it is not permissible to delay it after it becomes due.