Yeah, definitely some training is needed for that age group. It will be easier for you and me when we grow to be 100+ years old. She clicks on the green symbol that shows a video camera, maybe that helps to recognize. I am sure Google Duo would have an understandable icon as well, so you raise a good point.
> Firstly; she has not heard of WhatsApp
I am pretty sure she had not heard of FaceTime as well before you introduced it to her? :)
Disc: Googler.