I love both The Worst Witch and Weirdsister College, although it is a shame to see that many of the characters did not return in Weirdsister College.
In what way do you mean that Ethel Hallow has changed? If you mean the actress has changed please refer to http://www.imdb.com/title/tt0179061/ you will see that the actress Felicity Jones played Ethel Hallow in 'The Worst Witch' for 2 years (1998-1999). Ethel Hallow was then played by Katy Allen from 1999-2001. In 'Wierdsister College'however, Felicity Jones returns to play Ethel Hallow.
In what way do you mean that Ethel Hallow has changed? If you mean the actress has changed please refer to http://www.imdb.com/title/tt0179061/ you will see that the actress Felicity Jones played Ethel Hallow in 'The Worst Witch' for 2 years (1998-1999). Ethel Hallow was then played by Katy Allen from 1999-2001. In 'Wierdsister College'however, Felicity Jones returns to play Ethel Hallow.