All of the aunts and uncles
Are Clara, Arthur, Hagatha, Enchantra, etc really Samantha’s aunts and uncles?
share Uncle Arthur is for sure. There's an episode where Endora says that until he came along, she was an only child.
I used to think Hagatha and Enchantra were her sisters, but that would make Uncle Arthur older than them. And they definitely looked older than Arthur.
I had the impression that Aunt Clara was Sam's aunt on her father's side. She seemed old enough to be a great aunt and Endora never refers to her as 'Aunt". Of course that doesn't mean anything. I have two nieces and they never precede my name with "Aunt". My nephew does though.