Is the sister entitled to claim the remaining amount of the debt after the sale of the mortgaged gold without the knowledge of the mortgagor and in violation of the agreement? And is the debtor obligated to pay her former husband’s debt despite the creditor’s refusal to provide a promissory note or resort to the judiciary?

Your sister is not permitted to sell the gold, because you did not grant her an absolute authorization; rather, you restricted it by requiring your presence. If you cannot find the money to pay her back, and if she has already sold it, then she is liable for its guarantee. We advise resolving the issue without resorting to courts, in order to preserve familial ties. As for your husband's debt, you have no relation to it, and you are not obligated to pay it, whether the creditor presents the trust receipt or not.