I agree with what the other ladies have said. There is just one thing that I am questioning. When she sees her oncologist for checkups, does he/she do bloodwork that includes tumor tag tests? One of the tests that my oncologist does at each visit is a CEA. When my counts jumped from 12 to 29, that was the first indication that my cancer was back. There are several other tumor tag tests that can give the same indications.
I also hope that someone is going with her to her appointments. Not only is it good to have an extra set of ears but the moral support is much needed. Even though you can't physically be there with your mom, continue to let her know how much you love her and support her.
Perfume and incense bring joy to the heart, and the pleasantness of one's friend springs from his earnest counsel.