Cancer patients know?

All of you who are my friends know about my sister Dianne. She has lived well Beyond what the Boston doctors said. Two week ago, she said. My time is near. I'm going downhill and I know it won't be long." Then she looked at me and said, "but I'm ready to die." I had all I could do to hold tears back. God, I don't want her to go. As a Geri-Psych nurse, I've heard this from so many patient and they knew. Do you believe the dying know when the time is near? I need to talk about this. to keep my sanity. I want your input. Thanks my "Answer friends"