My brother passed away in June 2005, after a 4 year battle with brain cancer. A little less than a year ago, my oldest brother was diagnosed with pancreatic cancer (he, thankfully at this point, is in remission). There is no prescribed way to deal with it, other than to allow yourself to feel whatever you are feeling. In doing this, you allow other family memebers, and your sister, to be free to feel what they need to feel.