She didn't specify home defense. If we're going down that path, just let me get it in: AR-15 for home defense.
And thank you for not repeating the fairy tale of scaring a bad guy 'by racking a round".
I have seen some criticism of pump shotguns, in that an inexperienced or nervous owner could 'short-stroke' in a crisis situation, and fail to load a round properly.
In any case, I see the OP has gone to where the answers are:
https://texags.com/forums/34/topics/3110633She's buying her a guy a gun, so win/win, regardless of what she buys.