Mini 30, M1 Carbine, or SKS for wife
Any one of them will do and have adequate accuracy out to 100 yards which is not really needed in a HD rifle. You're chances of shooting over 25 yds in a HD situation are very rare. You will have to justify why the BG was still a threat to you at any range and the threat level usually decreases as the range increases.
I'd add a stock Saiga to the list (I'd pick the 223).
I would lean toward the 223 or 30 carbine. Use a SP or hollowpoint not a FMJ. The 7.62x39 offers no distinct advantage for HD if you're using a SP or hollowpoint in the other calibers.
I find the Mini 14 ot M1 carbine more user friendly and easier to feed (magazines) although 10 rds should see you through in a HD situation.
The safety on the Saiga is easier to find.
You need to let your wife decide what she wants. Don't do it for her.
I'm actually leaning towards the M1 Carbine as it is the lightest and smallest of the options. I know the round may be considered by many to be anemic, but I think for my purposes, it will get the job done.
The other issue with the M1 carbine is ammo can be pricey since you will want to use CorBon's ammunition to get the best effect.
The 30 carbine in SP or hollowpoint makes it a totally different animal comapred to the FMJ. I have seen it work well out to 100 yds or so. I see no magic in the Corbon ammo and Corbon themselves admitted they had problems getting it to feed reliabily. I've seen no problmes in feeding with conventional SP ammo.