[Pajamaman]

The onyx interface is easy enough, but not like normal android. However she could stay within a 3rd party reading app and never leave it. Alternatively you could install nova launcher which is a lot like a phone interface.

I too use alreaderx on the onyx, but i use alreaderx pro for eink. It has a simpler interface.

The onyx does come with a dictionary app, but it's not great.

FWIW I set up an onyx for my partner with alreaderx. She seems to go between the onyx hi and the alreaderx library system to find books. She almost never has to ask me help her. She can navigate an android phone no problem. Sometimes she get confused between the alreaderx library and the onyx hi, but the default app is set to alreaderx so it all opens in the same program. I set up the contrast options for her and she's never had to touch it.