Who is Happy, and where does Granny see her?

The Jilting of Granny Weatherall does not have a character by name of Happy. There are only two references to the word happy in the text. I have provided them below.

“Here’s Doctor Harry.”

“I won’t see that boy again. He just left five minutes ago.”

“That was this morning, Mother. It’s night now. Here’s the nurse.”

“This is Doctor Harry, Mrs. Weatherall. I never saw you look so young and happy!”

“Ah, I’ll never be young again – but I’d be happy if they’d let me be in peace and get rested.”