Well, I've been trying to think of this lately... my mom is in her last year, most likely. Of course, I'd love to be wrong. You can do a search for the thread I started, with my username and see all the good ideas that people had for me.
I'm doing video (and storing in more than one place) of stories, what she wants to tell my kids when they graduate, marry, have their first child...etc...
I'm also having her tell her stories to video..
Depends on what kinda of time you have.... but just anything to tell her that she's important to you... to your family.
I've told my mom that I love her more than before.... We have faith in God and Heaven.... told her that it's only selfish that we want her here...(told my dad this so far... will tell my mom in the end) and that we trust we'll see her again. I picture her rejoicing with all of our family....
Cancer sucks/stinks!!
I'm so sorry that you are dealing with this :(