Hmmm. The question presupposes that Eve did not have a belly button so it goes beyond the more common inquiry, “Did Adam and Eve have a belly button?” The problem is that the question as stated is not how things work physiologically. Eve’s baby would have developed like any other baby whether or not Eve had a belly button. So when Cain was in Eve’s womb (Genesis 4:1) he had an umbilical cord connected to the life-giving placenta until after birth. Since this is family friendly blog, I’ll leave it at that. But in case you feel robbed because my answer is so short, let me leave you with this little tidbit. If it’s true that Adam and Eve did not have a belly button, then it turns out that one of mankind’s most nagging suspicions has not been without merit after all—belly button lint is indeed a result of the fall.