The coven consists of three witches .
Hester is the leader character often being top in ranks and known to be an "illustrious witch".
Anadil is the "sidekick" or 2nd best to Hester although she is also top in the ranks.
Dot is known to be the most passive of the group although she is more nice to Sophie in the beginning the both of the other 2 witches.
Sophie was in the coven briefly in book 1 after Hester kicked Dot out but Dots back in.
The coven has been in all 4 books as antagonists and protagonists at the same time. The coven is in the ever never hand book as Hester writes tips and tricks for nevers .
In book 3 Hester says to Agatha that Agatha is part of the coven but Hester says if Agatha tells Dot that then Dot would turn them to mallah pudding .
The 3 witches are in the school for evil and are currently trying to find a schoolmaster as their quest in book 4: "Quest for Glory".