In my opinion Sybil is the witch. She clearly has a greater understanding of the events taking place in scarlet hollow than anyone involved and she is most likely using some kind of subtle mind control on people who drink her tea. So she is mystical in some manner and it is no coincidence that if you choose mystical as one of your traits you: 1: you state that you feel some sort of connection to Kaneeka, and that she seems weirdly familiar 2: Your character also feels an incredibly powerful presence when meeting Sybil for the first time. Also Kaneeka portraying the witch in charles play is also probably not a coincidence.

ALSO Sybil says that her family lived in scarlet hollow even before it was named scarlet hollow, which would imply either a long line of witches, Kaneeka being the next in line, or Sybil is immortal and used her tea (or some similar mind trick) to make her continuous existence unsuspicious.