I had the privilege of going through that journey with a very very good friend. I called her often and apologized once for doing so, assuring her that she did not need to answer my call if she didn't feel like talking etc. I had assumed that she was getting calls all day from people, but she said that, in fact, she actually got very few calls and so appreciated mine. The other thing I did, not sure if it was the right thing, was to do my very best to not be emotional when she talked about hard things. I felt like she needed the opportunity to talk without having to worry about me. If you wonder if you should call, talk etc, I would advise you to err on the side of doing it, of course being sensitive, but I think often people don't want to intrude and so don't make contact, and I think it is easy for the person to feel somewhat isolated. I wish you and your friend the best, she is fortunate to have you to care about her.