They should know better, but they don't. Know that you are in our prayers, and that doing the right thing, while hard, is ultimately worth it. They can open presents without you, your sister will be okay without you at her game, she'll undrestand someday. It is not like this "bed rest" thing is your choice, or that you've never had pregnancy difficulties before. You don;t get to choose your family, but you do get to choose your friends. We, your friends, will still be here for you.