You are extremely limited to the type of player that will play audio books the player in the link although it does not have big buttons it may be the only way to go, or maybe contacting the RNIB they may be able to help...
Have you tried your LOCAL society for the blind and partially sighted?? I'm involved as a volunteer in the one in the area where I live and I know they can provide lots of stuff to help people - even those with only a minor sight problem. And they can come to your house/mother's house to establish exactly what she needs. What part of the country are you in? I may be able to find contact details for your area.
I've found a society in Surrey that may be worth contacting - don't know if they provide the same sort of services as our Soc does, but it's worth contacting them before you rush out to buy something. I'll send the detail to your email address if that's Ok.
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