Good luck and may God bless your Mom. Tell her to hang in there!
If you or a sibling can go along with her on her visits to the docs, take along a tape recorder or a notepad and jot down what the docs say. After a while it all starts to run together, especially for the one fighting the battle.
The family often thinks there is nothing they can really do to help, but truthfully it helps a lot just to tell people you love them and you're there for them - it's like chicken soup for the soul.
Speaking of chicken soup, there is one of those "Chicken Soup for the Soul" books specifically geared toward cancer patients, reading it can really pep up the determination level seeing that other people have been in the same boat too... .