What should a wife do to help her husband who is overspending on his sister's wedding, despite their financial hardship and the lack of assistance from the rest of her siblings?

If a husband's spending on his sister's dowry leads to him falling short in his obligatory spending on his wife and children, then he is not permitted to do so, because the maintenance of the wife and children takes precedence. However, if he is providing for them adequately, then there is no objection to him spending on his sister and maintaining kinship ties, and the wife has no right to object. Nevertheless, she can gently and wisely discuss spending priorities with him. The wife should strive to maintain affection with her husband and encourage him to honor his parents and maintain kinship ties.