I am sorry to hear about your mother.
However, a person either has dignity or they don’t. There is a world of difference between having dignity and acting dignified, there are plenty of people who act and look dignified who don’t have a shred of dignity. Dying with dignity is accepting what God chooses for us regardless of how difficult it might be. The Jews who were starving and ragged as they were forced into the gas chambers had far more dignity than the Nazi villains who would later dress in their best uniforms and commit suicide rather than be captured.
So are you comparing the woman in the story to a Nazi?
Do you have any first hand experience with someone dying who’s body has been ravaged with tumors? This is not a tv or movie death where they simply close their eyes and are gone.