my mother is 88 and legally blind. She loves the Echo dot - she has one in her living room and one in the bedroom. I did all the set-up for her and it is linked to my amazon account. Your mother would need wireless internet in her residence to be able to use it.

An Echo, which has Alexa, or a Google Home device can be extremely helpful. You could purchase a low budget tablet or phone, so that she may have a personal account with her card information for payments and personal information. Audible is quite accessible, once it has been set up, and she’ll get to enjoy all the other features these devices have to offer.

Hi, the talking book library for the blind can hook your mother up with an accessible book player, and an entire list of audio books. This service is free.

It's probably better for her to have one, so it's registered to her as a personal device, and all that jazz, but it's not technically necessary on a day-to-day basis. My grandmother uses her Echo every day but the variable and non-standard layout of the Alexa app (used entirely through VoiceOver as she can't see the screen at all) is completely defeating. And that's when the app doesn't have problems.

Once it's all set up and registered, she can just ask it to read the books, and the app can be on anyone's phone, including yours, so long as you're trusted with her Amazon password. No app required for her. The downside is you have to know the full and exact title and recite it correctly.

Fun fact: you can do this WITHOUT an audible subscription. Any Kindle books owned by someone with a registered Echo can be read - they're just read by text-to-speech in the normal Alexa voice. That may be unpleasant for someone used to narrated audiobooks, but it does work. Again, you need the full and correct title.

Lastly, don't forget that the Echo is essentially a fancy bluetooth speaker. You can pair anything that has Bluetooth or is plugged into a transmitter, and the audio will come out of the Echo. For smartphone apps, the Echo even works as voice control (play, pause, skip, etc.). I haven't tried it with something not smartphone-based, but there's no reason it couldn't still work.

I am totally blind and use Alexa with zero difficulty.

She doesn't need a smartphone. You can set her up with an Amazon / audible account, or link it to your own. The talking book player is a good idea if you're in the US, but it adds a layer of complexity; I wish they would just write an Alexa skill. Anyway, no smartphone necessary; just wi-fi and a phone to do the initial setup.