2. According to Article 4 1 of the Marriage Law, the joint debt of husband and wife refers to the debt used for the joint life or production of husband and wife, or the joint debt of husband and wife. Brother in law's gambling debts should be borrowed by brother in law alone, not used for the joint life and production of husband and wife. Therefore, the personal debts belonging to the brother-in-law alone should be repaid by the brother-in-law alone, which has nothing to do with the wife. That is, my sister is not responsible for repayment.
It should be reminded that elder sister and brother-in-law should bear the burden of proof for personal debts belonging to brother-in-law. Article 24 of Judicial Interpretation II of Marriage Law stipulates: "If a creditor claims the rights of the debts incurred by one spouse in his own name during the marriage relationship, it shall be treated as the joint debts of the husband and wife." It can be seen that the debt incurred by one party during the existence of the husband-wife relationship is a personal debt, which is the responsibility of the husband and wife, not the creditor. Therefore, please collect evidence as soon as possible to prove that brother-in-law's debt is gambling debt, not for husband and wife to live and produce together.