Is it permissible to sell gold and help one's family repay a bank loan without informing the husband, and is that considered a sin?

Usury is a major sin, and family members must be warned against it. Nevertheless, it is permissible for a wife to help her family pay off their usurious debts, because the prohibition pertains to the origin of the contract. It is recommended for the wife to consult her husband before offering help, though it is not obligatory by agreement if the amount does not exceed one-third of her wealth. According to the majority of scholars, it is obligatory if it exceeds one-third.