My mother in law was diagnosed with liver cancer three months ago but she doesn't have any pain?

She has had bowel cancer inthe past and had a large amount of her bowel removed. As a result she has lots of dietary problems and pain when going to the toilet. Anyway, her liver cancer is in the gall bladder and lymph nodes but she doesn't seem to have any pain or any real symptoms. Also, they said it's inoperable. I would have expected her to be a lot worse by now. Is this lack of pain normal?? She gets breathless and seems to have a diminishing appetite and seems tired but thats it. Any insight would be geat!