If she is stuck on shotgun I would suggest getting her to actually fire a shorter, 12 gauge. If it is too much for her then a 20g youth shotgun would be an excellent choice. You want it to be as compact as possible if using within a home.
I would suggest finding a range that offers handgun rentals and find something you both like. Handguns are very personal and what works for some might not work for others. Other than that, I would definitely suggest 9mm as is relatively inexpensive to train with and is easy to find.
Lightly used with a low round count. Wilson Combat thin grips installed. Asking $500 but willing to consider offers - not really looking for trades.
Included:
2 - 15 round factory magazines
2 - 17 round factory magazines
Original Beretta Grips
Kydex Holster
Wilson Combat Short Reach Trigger -...
I was in the same boat about 6 years ago - the only one I know of is Aklys Defense in Baton Rouge. That said, I really didn't have a good experience dealing with them. It took them a year and a half to finish the job. The work was good but the service not so much.
Selling a 14.5 upper with a Colt Socom Barrel w/ FSB, BCM upper receiver, pinned BCM extended flash hider, and Magpul MOE Flip-Up Rear Sight installed. This upper has around 200 rounds through it as it was on a spare build that didn't see much range time. There are light specs on the receiver...
For me the Mossberg 590 with 18.5 inch barrel, magpul stock with 1 spacer, and bead sight works - it patterns S&B #4 buck pretty good within 20 yards so I keep that handy. Very fun!
Whatever you go with, make sure the ammo you choose patterns well within the distances within your home.