Certainly been discussed here before, but worth repeating. Even Rob Pincus, back in the Valhalla days, determined bird shot at SD ranges #4-#7 shot, is devastating at 7yds, or less. Handgun ammo, as well, needs to be considered with interior/exterior, neighbors, etc,... Even frangible ammo in an AR platform is very effective for SD.
Each of us, has already made that analysis of their particular domicile. Apt., stick built modern homes with sheetrock and vinyl siding, concrete stucco, proximity of neighbors, etc,...
Also identifying lines of fire, bookshelves, fireplaces, interior walls, adjoining bedrooms, and most important:
Simply having some sort of practiced plan, rehearsed will help. Especially, if kids rooms are on the opposite side of the house.
If your child screams in the middle of the night, of course you investigate, how well do you know your house in the dark?
Where are potential ambush points if there is more than one BG? Where are your strong defensive/offensive positions?
Who is already calling 911? You? Spouse?
How to talk to a 911 operator, etc,...
Kids, especially younger ones need to know a "key word", or "phrase", that the kids will immediately understand and react to.
Under the bed, get in the closet, lock the bedroom door, stay low, go to the Master Bedroom, whatever. It should be like the old Dick Van Dyke commercials about housefires. Stop, drop, and roll,..or how to get out.
Same premise with an SD situation. Planning and including your family members, makes the unthinkable hopefully more survivable.
Welcome Tommytat2, always a good topic to review, and revise.