Medicare and some others do pay for home health care... visiting nurses and aides are cheaper for insurance than nursing homes are. Have you already checked it out? It's a tough call to make for a family, I know. Prayers that whatever happens next is the best path for everyone, including Nana, and including you.
But, the way she is now, she can't be alone...ever.
So, at a minimum we're looking at 8-5, four days a week. Medicare won't pay for that.