Does she use text/WhatsApp, or similar? I’m off and on chemo for the foreseeable, although my husband is well, so not a comparable situation, I know that at times I just do not want to talk, even the phone seems too much effort. Whereas written communication keeps you in touch and she can answer if and when she feels able to.
It is a situation that is so hard to get right, if not impossible, she must feel trapped in a nightmare with no way out. Sympathy can be hard for some people to bear.
Books, suggestions for films or tv programmes, just general chitchat. Try Texts, messages, little pretty cards. Don’t give up.