Hello,
I can completely understand your frustration with your sister. My Mother was diagnosed with bile duct cancer in May. She is 63 and my father is 82, so when she first got out of the hospital she decided she would like to stay with us because of the level of care she needed (we live right next door in her old house so it was not too traumatic of a move for her).
My husband and I have completely taken over her care as well as raising 5 children and me being pregnant with the sixth.
My sister lives about 5 miles away, and will stop in maybe 1 day a week. My mother has been hospitalized 4 times since her diagnosis and the same sister (who does not work and her youngest is 5 years old), cannot seem to find the time to get to the hospital. The last time Mom was in for 17 days, and my sister visited 2 times. Meanwhile, we went every day because I know what it is like to be in the hospital and have no company. Just yesterday, my sister went to Six Flags which is only about five miles from the hospital, and she did not even stop there on her way home. It is very frustrating because all I hear about is how busy she is and how stressed out her life is, and I feel like she does not even have a clue...
What my husband and I both say is that you can't "change the spots on a leapard" and that at least I will have no regrets if my mom does lose her battle with this disease. I am sorry to ramble but I completely understand how you feel.