obviously not everyone is the same, but in my case my grandpa (72yrs old) got a XS Max a few months ago as he upgraded from a 7+. i thought he would have trouble using it but nope he didn’t need help figuring out the gestures after i showed him ONCE. Just ONCE but after that he learned himself pretty quickly how to navigate the phone which surprised tf out of me as he doesn’t know jack about modern tech

i would personally teach her how to use the phone incase she struggles but if you do it shouldn’t be too bad. with that being said definitely opt for the 12 pro but make sure the battery has decent health