I can't agree with all of your post. Most folks swear by the "rack" noise of the shotgun scaring off the bad guy. In my opinion, all that is going to do is alert them to your location.
And contrary to popular belief, you still have to "aim" a shotgun, especially in close quarters.
I agree that a pump action 20 gauge, with a youth stock is the best bet for a woman in the home, provided she is proficient with it.
If you were coming into a dark building for me , that giving away position would be a serious factor because I am a well trained individual in tactics an survival..your avg scum bag hairball isn't and the have to aim, I took that as a given of course you have to..we don't really disagree, I looked at it as teaching an inexperienced person survival not turning them into a tactician as it is unlikely the avg housewife will invest that much time and effort. I am a trained individual and if a person in a dark room racked a shotgun,,my training tells me to back off and re-assess and shift gears. Now as a LEO, I would HAVE to devise a way to deal with this which is whole extra page, but as an intruder I would opt to leave and find an easier victim, he doesn't want his intestines turned to hamburger either.
I meant to recommend the .20 ga. thanks for getting my back on this one..owe you a cold beer.