Family and food

Hey guys. So recently my husband and I have been having financial problems. We got a few things to keep us afloat and stuff for our 6 month old. His sister wants to come over and she has 2 teenage kids. Whenever they come. They do help and it's a joy. But they do stay inside all day and watch tv and eat a lot of our food. Usually I don't care but right now. We can't afford anymore groceries until a long time. I'm not sure if I should just allow it or tell my husband to say something.