We have all said what we will or will not do in a violent situation where you or a loved one is at risk of bodily harm or death. There is a common misconception that when it counts people will rise to the occasion. The truth is you will do what you have been taught to do. While there are exceptions, if you haven't been taught to respond to a threat, you are most likely to panic. Before anything happens you must observe a threat, orient yourself to the threat, decide on a plan, and act on that decision. That is called the OODA loop. How you get from orient to act can determine whether you live or die.
I'm no super ninja bad ass but I have spent a large portion of my military career as an MP both in garrison and forward deployed. I would highly suggest that we all sit down with our families and actually come up with a plan of some kind. Figure out what is best for your situation. If that plan involves a firearm, take a dynamic firearms class. Yes I said LEARN TO FIGHT WITH A GUN IN CONFINED SPACES if your plan involves use of deadly force.