I think that it is possible to be looking at others through your Nana's health. I am 61 and have arthritis in my hands and knees. I am healthy, can manage to do most of what I always have done around my home, but boy, do I feel it differently now. My heart still tells me I am 35 but my body claims otherwise. I am as active as I was, but given how things are changing with me, I know that in 20 years I will not be doing yardwork, shoveling, repairing tools, etc that break, and still have any life in after those chores.
I used to clean homes when I was younger and many of my clients were older women alone. They had not been realistic about their physical limitations as they aged, and were reliant on others to manage their day to day chores. It was not a great place to be, and had I not deeply discounted my services they would not have been able to afford the cleaning. I just kept my own Mom in mind and treated hem the way I would have hoped my Mom was treated if she as in that boat.
@ThistleMae - I think it is a good idea that you are thinking ahead. I am 61 and right now life is fine. My DH is here and is healthy enough to manage all the chores and repairs that make home ownership difficult for someone alone. I confess to worrying about how I would manage should something happen to him, and it is not a pretty thought. He would be horrified to think I let the home go, but also would be devastated to think I was not able to properly maintain it.