I don't mean to miss the point of your topic, but if she enjoys shooting rifles and isn't so keen on shooting pistols and isn't going to carry anyway, would you ever consider a pistol caliber carbine?
Wow, I'm a complete idiot
. TBH I really didn't think about it. How maneuverable is something like that in a house? I don't expect her to go clearing rooms but still. If it's relatively short you might have just hit the nail on the head.