An Amazon Echo. No screen, no menus to learn, you can purchase audible books (read with a human voice) or kindle books (read with a computer voice) and just ask the echo to read the book you want. You can also use it to play music, read news, etc.

I don't personally own one, but I know a few (mostly older) blind people who aren't great with computers who have really enjoyed using an Echo, and a lot of people mention successfully buying them for family members in similar situations.

The Amazon echo is entirely voice controlled, and can read Audible.com or Kindle Books. That's the easiest, by far. It can also play radio stations and podcasts.

Otherwise, look into the victor reader stream. Although that may be more than she wants to learn.