When my older and only sister was ill she triggered me a lot. I wish I had set firmer boundaries, as Cocosurviving points out. It's healthy. I could still have frequently talked with my sister, but she got away with a lot of abusive stuff because of her illness --- guilt tripping, and all the other manipulative stuff. Just because people are ill or dying doesn't mean they have a positive personality change. I hope wherever my sister is, she approves of this post. (See, she still guilt trips me from the Beyond! Haha.) I think the best advice when someone close to you is very ill, is you need to take extra special care of yourself, because the situation is a real energy zapper.