Right away, start leaving radios on, and pin notes (different ones each day) to the front door "Joe, if your Uncle doesn't come to the door, just email him or call me instead - he's been having headaches and stays home sometimes." or "Lisa - don't bug your father; he's got a hangover and is in a real bad mood and I couldn't find his pistol to take away while he's asleep," or "Ken busted his ankle last night and stayed home on doctors orders. He can't come to the door until we get him some crutches, so just give me a call later." Those might at least give some punk the idea to try another place TOMORROW, while you're still getting your other options in order.
You should keep the 1911 on you if that's what you're most confident with. Get 'frangible' ammo if you really are worried about penetration (Glaser Safety Slugs, etc.), and watch your backstop if you DO have to shoot. Likely you won't have to - these types are usually just going to 'confront' you if they make the mistake of not thinking you're home but you actually are home and they walk in on you or vice versa. Biggest danger would be if your wife is napping or in the shower or some such.
If some creep is coming at her, she'll shoot a 12 gauge, recoil or not, but you could let her practice with some very light target loads of small shot (which do a fine job of stopping bad guys anyway).
In the long run like someone else said, get her to a range as soon as possible and let her shoot ALL your guns and let HER pick the one she's most comfortable with. If it's the AR-15, penetration will be a concern, but
her needs must come first. They DO make frangible rounds for .223 as well, by the way. Of course the idea is that if she's a good shot with whatever she chooses, and the bullets are constructed right, neighbors won't be endangered. (i.e. if the gun she handled far and away the best was a .444 Marlin, frangible .44 pistol bullets wouldn't endanger neighbors much, but I'll bet they'd rearrange the bad-guy's innards for him.)
Consider letting her shoot other guns, and if she finds one she likes better than any of yours, that you feel has power, limited penetration, and so on, buy one for her or trade yours for one for her.
I agree about 'inside shooting' the high-velocity guns - only if no other option were availabe. That's why I'd go for the shotgun, and the .45 Colt or .45 ACP guns first.
Back to the prevention - yes - get a DOG, even if you have to just 'borrow' one from the pound for a week until you settle on one you want for keeps; the dog will give you or wife some warning if you're in the shower or basement or whatever when trouble comes knocking.
The BEST thing is if they think you're home - they will go elsewhere, then. Be sure that your wife knows this, because if she's too afraid to say anything when they knock, the next thing she knows they will be in the house and she will HAVE to shoot - - - far better she answer (NOT open - just answer) the door. As far as having a gun, she keeps the element of surprise if she doesn't say "I've got a gun", but if saying that is needed to keep pervert/burglars from coming in knowing she's home, it could save her life by preventing a confrontation, or save lots of legal hassles and a lifetime of looking over your shoulder in case the deceased burglar's next of kin want revenge.
Good luck. Too bad our Holy War on Drugs and our Welfare State society have so destroyed our society...
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