In the circle who was the first to know about the magic?

Diana was the first one to find her family's Book of Shadows and discover her parents' connection to the others in the Circle. She eventually told Adam and the others afterword that they were part of a coven of witches.

Jake (maybe with Nick too)....
They found the book first, then Jake left, and Diana found it!

But it's never said exactly! The only exact thing is that Diana was the one who told everybody about everything

daiana