I actually don't find that weird. It would be nice if she could use a basic cellphone so she could call or text someone if she gets in an emergency outside the home. But stuff like FaceTiming the grandchildren, I get how she sees that as unnecessary. She sees them 1x a week and gets updates from you and your wife, perhaps that is enough for her? Tablets, sure, but from her perspective she already had resources for getting the news, weather, and entertainment from other sources so why add something else?

I kinda get it. Why add more to your life if you're satisfied with what you have.