So many are about murder, sex, violence. I'm running out of ideas for authors to look for. Just an intertaining, subject or story. She already suffers from depression, so why are so many books now a days depressing? Evanovich, Macomber, Braun, are a few we try but another author or two would be nice.
I would suggest the Chocoholic mysteries or Donna Andrews' "bird" mysteries for not having lots of sex and violence and not being so depressing. My mother also finds Mary Higgins Clark acceptable, although hers aren't quite so light-hearted as the first two I suggested.
I haven't read any of the "Chicken Soup" ones but hear that they're uplifting and fun.
Or, if you can get P. G. Wodehouse's Jeeves and Wooster books on recordings, those are funny and silly.
Kind of light are Lillian Jackson Braun's "The Cat Who..." mysteries where the cats kind of help solve the mysteries in an oblique manner. Or, the Sneaky Pie Brown series (by Rita Mae Brown) where they actually do solve the mysteries could be light-enough, too.
The Library of Congress has a program run through the states that supplies digital book player and books in digital format. You sign up through the state you live in. If an individual qualifies as being blind,( a Doctors statement) the state library will send free of charge to the participant a digital player designed for ease of use and a catalog of books that will be sent through the mail free of charge. Mom has been on the program for about 6 years . She started the program when she lived in Virginia and it transfered with her to Texas. The new digital player is so simple, even she can use it. Also a person can buy the blank digital cartridges ( llibrary staff should be able to tell you where to purchase them) and download books at home one you get authorization. The digital cartridges are actually a flash drive set into a special cartridge and can be re used. The books can only be played on the digital player the state library suppies.. It is a wonderful program for those with macular degeneration or blindness.