My Sister Is 50 Yrs Old. She Has Down-syndrome And

My sister is 50 yrs old. She has down-syndrome and Hep C, from heart surgery in the early 80's. We found out 7 years ago about the Hep C, she was ill and we did not know why. A year ago she took a bad convulsion, they have continued. She is in a nursing home. She can no longer swallow pure aide foods. We know her brain has shrunk a lot. She no longer "lives" she is almost vegetable state. She will start a feeding tube in the next day or two. The Doctors gave her 6 year to live, 7 years ago. We know the time is soon. What are some end , end signs?

Thank You,