I'm certainly no defensive firearms expert, but I have done some reading ... while contemplating keep in mind that the 22 rifles/pistols and 410 shotguns simply do not have sufficient stopping power.
Even higher powered rifles offer an aiming disadvantage.
For home protection, everything I've read says to get a 12 guage pump-action shotgun and load it with #1 buckshot.
With that says, I agree with your sister. For many of us the thought of blasting away another human being boggles the mind. While I have no doubt that I could do it to truely protect myself or my family, not having been in that situation, it would be hard to know when to pull the trigger.
Does anyone know the legalities of defensive use of firearms? It seems that I've read you can't shoot someone simply to defend your property - it had to be for protection of life. Do they have to be INSIDE my home before I can pull the trigger?