That poor little dog. It hurts my heart to know that she is ready to go home and doesn't understand what is going on. I am also sorry to hear about the loss of your grandmother. I am sending you nothing but positive vibes and happy thoughts.
Sadly, we have to walk away from our animals throughout the day. Being with your grandmother for twenty four hours a day may take a bit of a toll on her. Being around another animal may be helpful, though I don't know if that's something you can consider. My best advice is to buy her lots of distracting toys and spend a good amount of time with her when you are home.