That's good to hear that your family prepares a good amount of food for you and that it gets better for you guys as well! Do you/your family have some favorite dishes that you bring?
My grandmas had the same worry - that I wasn't getting enough food. But after eating this way for 4 years, they realized that I'm even happier and healthier than before I went vegan :)
RE: Holiday dinners as a vegan - past & present