For a 107 year old, she was very good using her cell phone !!!

You overlook an important point. The effect that caused her to NOT age also means that her brain functions and cardiovascular system did not degrade either. So even though she may have been over 100 years old she would still have the brain and mind of a younger person. Therefore she would have accepted and tackled new technology just like anyone in their 30s. But with the wisdom of an much more experienced person. Wise enough to know that even though your phone rings, you don't have to answer it. The younger generation don't seem to grasp that yet!

..*.. TxMike ..*..
Sometimes I think we're alone in the universe, and sometimes not.

That a silly thing to say. I know a lot of older people, and they have been using cell phones since the 80's, changing with the times. You sound very young. Everyone one I know is very proficient with computers, tablets, and cell phones.

She had to blend in somehow for her appearance. And I know many people, including my grandmother who's in her 70's that have iPhones.

I actually thought the exact same thing. I thought it would have been a nice, quirky addition to make her fumble with technology and require help, making her seem more like an old woman in a young woman's body.

I don't think the trouble that older people have with grasping technology has anything to do with ailing mental faculties. It has more to do with neurons already being mapped for different things and the inability for the brain to remap them effectively. Given the magic already occurring in this story it's easy to write it off, but she seems to have an affinity for older music, older style, and a more classic taste in general which is consistent with the brain becoming attached to certain things when a person is more impressionable and then becoming a bit closed off to newer styles and music as time goes on. So it seems a little inconsistent I guess. She acts old in some ways, but not in others...

Also everybody knows older people who do fine with technology, but that's likely one of their major hobbies or interests. They make a concerted effort to stay on top of it, unlike younger folks who just get it because they never learned anything different.

She was trying to pass through life more or less incognito.

There is no reason she couldn't have learned to use a cell phone just like anyone else. Besides, she was still youthful, which included brain function--not that using a cell phone takes a genius. The main reason some old people never learn to use cell phones thoroughly is simply that they're not interested. I'm seventy, and I couldn't possibly care less about cell phones. I can dismantle a four-barrel carburetor, fix it, and put it back together. Can you?

Looking how my sister e.g. is handling a PC, it is imo not an age thing, but more a thing of handling. Older people just often not seeing in changing their used ways, so why should they adopt. But of course also worsen eye sight and less control of hands does not help with such a flimsy smartphone.

She adapted so that she would fit in.