Mother in law pushing too hard!!

My mother in law is pushing my husband and I to have a baby. We both want kids but not right now. He's 21, I'm 19. She won't stop. She keeps telling us that we should have a baby now. Her most recent comment was, "You know, Christmas would be the perfect time to announce that you're pregnant."  We've told her several times that we just want to wait a while longer. We've told her that we just won't come around anymore if she can't stop. But neither of us want to cut ties obviously.