If your wife benefits from that money in paying off the bills or the like, then there is no blame on you because of that. As for accepting that gift from someone who won the lottery, we have pointed out in Fatwa 99768 that if the ill-gotten money is prohibited in itself such as stolen money (which belongs to another person from whom it was taken illegally), then it is not permissible to accept it as a gift. But if it is prohibited because of the way it was earned (but it belongs to its owner), then some scholars allowed accepting a gift from someone who earned it because of the statement of Ibn Mas‘ood : "Benefit from it and the sin will be on the one who gave it."

However, there are other scholars who prohibited it, and this is better to be on the safe side, as long as there is no necessity to take it.