I think it was 44Mag who mentioned above that pepperspray, lights up the room. Amen.
Pray your wife never has to defend herself but if that lcp comes out it is to stop the attacker. Hit the threat and keep hitting it until it is no longer a threat. No longer a threat just means no longer attacking. High center mass (read chest) is the muscle group attacking you whether using a hammer, knife, gun or fist. Hurt it, hurt that muscle group. Don't shoot and observe, keep hitting it till it becomes obvious they are out of the fight.
(Otherwise they will kill or hurt you, that was established before you presented your weapon.)
Guessing your wife, like you, is a nice person. The only assistance you render a perpetrator is on the 911 call mention you need medical help. Don't go close no matter what whinning they do. They attacked you and are still a threat to you when you make the call. Even if they don't appear to be conscious.
Always amazes me when people expect an instant kill shot with any caliber. Especially on a hunting forum.
Best option is to see it coming and avoid. Trust your instincts, if they feel wrong get away...