Laura I'm so sorry about your Grandma but I'm sure she'll love visits from your sisters and yourself. My 81 year old husband died from cancer only a few weeks ago. He gradually slowed down and slept much of the time but was always responsive when any of the family visited, he loved seeing them. I don't know how recently you've seen Grandma but if it hasn't been for a while you'll probably see some signs of frailty which might shock you a little but she's still your Grandma so please don't be scared. My best advice is just be natural also ask her if there's anything she would like you to do, or get, for her, and act on her reply. I was with my husband 24/7 but inevitably when either of our sons visited he asked them to do things, always something I'd already offered to do or could do easily but I suspect he was trying to take some pressure off me. He was always worn out after their visits but showed no sign of it when they were here so maybe a few short visits rather than a long overwhelming one? Maybe your Grandma would enjoy you massaging her hands with cream or  gently washing or brushing her hair, anything she loves and makes her feel better but finds difficult to do herself now?  Don't feel guilty at all that she's dying, it happens to us all, but you'll be making it much calmer for her just knowing that you love her. I don't know if this helps you at all but I hope it does. Most of all enjoy being with your special relative.. xx