I do think all the modern conveniences are overwhelming for a lot of people, and how they react is the thing. Just think if you weren't good at reading, like so many are. Perhaps she was never diagnosed, but is dyslexic. There could be so many reasons she avoids technology, and perhaps her back was up feeling out of place amongst the rest of the group that was obviously coping. Or perhaps she was scammed and didn't want to be seen as stupid.
I'm afraid my older sister is like this. Overwhelmed and basically ignores anything new. She has a clunky old computer, but no cell phone. We gave her an answer machine for her land line years ago, but she never set it up. Doesn't record tv shows because it would be too confusing, etc. When her husband died, my younger sister helped her through all the paperwork with insurance, banking, bills etc.
The next time you see your friend, maybe ask if anything was said to upset her, and offer to help, or find help for her.