Question about failure to thrive in elderly?

My Grandmother has had a lot of loss in her life. She lost her husband in 2003, and both of her children in 2005. Almost a year ago she decided that she did not need any of her medication any longer (she was on numerous medications for blood pressure, cholesterol, iron for anemia). At this time her doctor suggested we enter into hospice which we did. Not long after this she lost the ability to walk and stand on her own. After a series of falls we entered her into a nursing home because due to my work schedule and being pregnant I was not able to take care of her at home. Since being in the nursing home she seems like she is wasting away to nothing. When she first got there her blood pressure would spike to a really high number but has since stabilized. They also think that she may have had a stroke that left her with vascular dementia but they are not sure because they are not doing any testing. When I am not there she talks out of her head and does not make coherent sentences. When I do go or if they bring her pictures of her family she can make coherent sentences and she can make sense when she talks, although most of the time she will say things that don't make sense. Right now the only medication she is on is an antidepressnet, ativan 2 times a day and pepcid for indigestion. There is a standing order for haldof but they did not have to give it to her at all last month and only once this month so far. In talking with the hospice nurse she is thinking she is going to consider her "failure to thrive". At this point she stays in a chair all day and is on a chopped food diet because of difficulty swallowing (they had to give her the heimlich 2 weeks ago). They say some days she talks a lot and some she doesn't, and over the last couple of months she has definitely lost weight. We are thinking of bringing her home to care for her (with the help of a hired cna) what will her prognosis be. We are worried she may become aggressive or mean and I am not sure if I can watch her just waste away. Right now the only time she is aggressive is when they are moving her from bed to her chair or during bathing. Also how long can someone live in her condition it seems to me like she is suffering, I know she does not want to live any longer and has for years said she just wanted to commit suicide she never understood why God took her family and not her. The only other medical concern she has is over the last couple of years she has tested positive for blood when they have done rectal exams. They never investigated that further either because they said the testing would be worse for her. Thank you for the help!