My family has done a great deal of research into this and so I wanted to share what we found so that hopefully it will help some of your family members.
For diet, I would very strongly suggest that she completely drop refined sugars and corn syrups. Cancers feed on things such a glucose, so any things that becomes glucose in the body should be avoided (honey is alright in small increments, but I would strongly suggest Stevia because it's a plant-product and not an artificial sweetener). She should drink lemon before bed (fresh squeezed in a glass of water, a little stevia is fine but nothing that makes glucose). The lemon kind of cleanses the body- then the cancer wont have anything to take into grow. In the morning she should try to wait to eat as long as she can and the first thing she should take in is something like a Vitabev. My mother mixes Terramin clay in with hers for added benefit. This gives the cancer only vitamin to take in, and since it's been starving that's what it will take in. She should wait at least an hour before eating food. Raw vegetables should be eaten plentifully, proteins should be small in comparision. You want her take life in to her body, and most vegetables loose a lot of that when they are cooked. Starches should be eaten sparingly.
Exercise; I agree that exercise is good. I would strongly suggest Qigong (in China it is used a lot in hospitals) because it works with the energy in the body and helps to remove negativity that the cancer might be feeding on.
For pain; Sometimes the Qigong can help but I also suggest massage for muscle and bone pains.
Belief; Don't give up on her. Believe you can overcome is half the battle. The first hospital my mother went to said, "You've got a year at the most, we can give you chemo and that might give you a few more months but you're going to die either way." She went for a second opinion at a more specialized center. The next doctor said, "Well, you can't sue them for it, but that is pretty terrible. If one thing doesn't work then we'll try something else."
Imagine how much better everything is with a doctor that believes he can help her recover.
Think about how many stories there are where the person goes to the doctor for a sprain ankle, or a migraine, or something to be told they have cancer and it's been there for months (or even years). Then the cancer speeds up its progress and they die soon after (in one story I read the lady died the next day). They hear 'cancer' and think 'well, it's over for me," and they don't believe anything but that they're going to die. They end up being killed by the very belief because it's all that negative energy that's feeding the cancer.
I have seen video of cancer tumors receding just by surrounding the person in people who are feeling themselves with the feeling that this person before them is a completely healthy, energized being. Hope, belief, prayer, it matters a lot.
I hope this helps someone, I'm not saying not to listen to your doctors, but it can feel so helpless. These are just things that you can do personally to help yourselves and your loved ones recover.