Regarding Post 8,
I don't recommend a guy choosing a firearm for a female. I'd rather her choose her own firearm, if any. Here's a website which both of you can read, specifically the "Choosing Firearms" section in this thread's matter, but try to read all the other sections, too.
https://www.corneredcat.com/contents/
My experience is LE. Even if the LEO was a 60 y.o., 125#, 5'7" female, she would be qualifying with a Mossberg 590A1 twice/year using both 1 oz. slugs and 00 buck. Some of these LEOs were 5'0", 21 y.o., 100#, with others of various other ages, weights, and heights.
I think her desire, training, and commitment will play the most part in whether a shotgun of any gauge, is what she'd want to choose.
FYI, many, whether male or female are really liking and choosing to go with the AR-15 over the shotgun when given the choice. Policy, btw, mandates if OK'd for an AR-15, the LEO must still qualify and maintain proficiency with the 12 gauge shotgun (at the dept. where I worked).