My grandmother is eating very little and sleeping very little. Is she giving up on life?

My grandmother is coming August she'll be 90. when i started taking care of her she was about 175lbs/she now 130 lbs he just said give her what she wants if she'll eat. she has gotten to the point she eats very little, sleeps very little, don't want to be washed up, she lost her only sister 2 years ago this coming May and has been going down hill every since. i think she good when it come to remember things. but don't want to do much of anything anymore. and if you try and get her to move around, walk just do something it a fight, she know how to tell you to back off, she becomes angrey. so just make sure i have food for her if she eats it or not, i make sure she clean everyday, but she has started to to strange thing. the other she took a poop in her bedroom trash can and then told me she did not do that, all this after i had her sit on the torlet for about hour. for the last few months she just talk about her family that she grow up with and talks about how tried she is, she told me i would understand it. she feel like the life has been sucked out of her and she ready to go because she has no family, she don't count her kids, grandkids. they are not her family. i told her we are and she said she know that but it not the family see came up with. Is she giving up on life.