A 12 ga is fine for someone that's become comfortable with recoil.
Not a raw beginner.
Maybe it's just me, but I would assume that someone using a weapon for home defense would at the very least practice with it a bit to get a feel for it. Yes, I know what they say about assuming
The first gun I ever shot larger than an air rifle was a 12 gauge 870 - recoil really wasn't that bad, even on my (at the time) 15-year-old 140 pound frame. Sure, it kicked, but it didn't take me too long to figure out to lean into it and absorb it.
At the WallyWorld in my town, there is 1 employee who works the gun counter that even owns
a gun. It is not
the place I go to for advice.