I second Glorianny's suggestion of a heated throw. They are very cosy, and if she's too tired to do much except watch TV she might appreciate one.
I also recommend sleep headphones, so she can listen to music, books, hypnosis or other sound apps in bed or whilst having chemo. This sort of thing. I love mine, and listen to an app with rain sounds which helps me sleep, as I feel snug and dry listening to it. I sometimes play audiobooks, too, but you can choose anything you can play on your phone. You bluetooth them to your phone or iPad/laptop, and once they are set up they are very easy to use (setting them up is easy too, but if she's not used to Bluetooth you could do it for her).