Is it permissible for my family to go to my mother’s house and eat from the leftover Thanksgiving food that she did not throw away?

It is permissible to eat the food of Christians because it is pure and respected, in accordance with the Almighty's saying: "The food of those who were given the Scripture is lawful for you and your food is lawful for them." So, it is permissible to eat their bread, their staple foods, and what they have cooked or prepared of foods and sweets. It is permissible to eat the food after their celebration has ended, as it is better than being thrown away.