George was the man to whom Granny was engaged when she was twenty. He jilted her at the altar on their wedding day, and sixty years later, the memory of the pain of his abandonment still has the power to leave Granny bewildered and upset.
John was the man Granny actually married. They shared a number of happy years, and raised a family, but he died a long time ago. Granny feels somewhat awkward remembering him, because in her mind he remains forever at the age he was when he died, while she has aged and changed in the years since.