Great grandmother on hospice

So my 92 year old Great grandmother is on hospice and all she does is sleep day and night we can't get her to do anything she doesn't eat or drink water it's been this way for almost a week any idea why? (Nurse says that's just what old folks do) 🙁
*** Thank You to the three beautiful ladies for caring enough to comment. It helps some. I feel broken and absentminded. In Denial. But thank you