Understood. Can you ask her to bring small appetizer or side dish that accidentally gets dropped destroyed and can't be used? Or if there's grandkids tell her you want her to buy something so she won't be tired and can spend time with the grandkids.

I wouldn't destroy it but suggesting her contribution be something really optional like nachos or a dessert is a good way to avoid hurt feelings if people don't eat it, they can just say they filled up on the main and other dishes

Good point, destroying serves no purpose.