Is it permissible for the wife to keep her money to herself and not help her husband build his house or buy a car for work?

A woman is not legally obligated to spend on her husband from her own money, unless she donates it willingly, or if the husband stipulates a portion of her money in exchange for allowing her to work, in which case she must fulfill this condition. Although a woman's financial assistance to her husband is not obligatory, it is considered a noble virtue and a perfection of good companionship.