Then Apple changed the UI a little bit. I can't begin to explain it to her over the phone in my second language, because for starters, I don't have a non-updated device to be able to compare and find the exact difference. I felt a bit of a jar and was able to roll with it, but couldn't tell you what the difference is exactly.
LTS (guaranteed non-change for existing features, at the cost of possibly not getting all new features) for UI would be amazing.
And do not get me started on the drama involved in an iOS major version update and the requisite iCloud password entry to even start the phone. She has the password written down, but since it's helpfully hidden as she types, she can't see that she was a letter off or missed a shift. I ended up sending her to the Vodafone corporate store with her password and 3 reset answers to have one of them type it in for her, as we're on the other side of the country, and she kind of needed to be able to make and take phone calls.