Se você está falando sobre o filme de 1939, nenhuma bruxa do sul é mencionada. Eu pesquisei o script de filme on-line e nenhuma instância de "south" foi encontrada. No filme, Glinda é a Boa Bruxa do Norte. No livro, Glinda é a boa bruxa do sul. No filme, Glinda realiza as funções que o livro Good Witch of the North realizou.
In the 1939 film version of The Wizard of Oz, Glinda is the Good Witch of the North, not the South as in the book. She is played in the film by Billie Burke. Glinda performs the functions of not only the novel's Good Witch of the North and Good Witch of the South, but also the novel's Queen of Field Mice, by being the one who welcomes Dorothy to Oz, sends her "off to see the Wizard," and orchestrates her rescue from the deadly poppy field in addition to revealing the secret to going back home.
Fonte: Wikipédia
Se você está falando sobre os livros, Glinda é a Boa Bruxa do Sul. Há uma Boa Bruxa do Norte, mas ela não é muito desenvolvida.
Ela aparece no Capítulo 2. O Conselho com os Munchkins.
Uma descrição de sua aparência:
Three were men and one a woman, and all were oddly dressed. They wore round hats that rose to a small point a foot above their heads, with little bells around the brims that tinkled sweetly as they moved. The hats of the men were blue; the little woman's hat was white, and she wore a white gown that hung in pleats from her shoulders. Over it were sprinkled little stars that glistened in the sun like diamonds. ... But the little woman was doubtless much older. Her face was covered with wrinkles, her hair was nearly white, and she walked rather stiffly.
Explicando a existência das quatro bruxas:
"But I thought all witches were wicked," said the girl, who was half frightened at facing a real witch. "Oh, no, that is a great mistake. There were only four witches in all the Land of Oz, and two of them, those who live in the North and the South, are good witches. I know this is true, for I am one of them myself, and cannot be mistaken. Those who dwelt in the East and the West were, indeed, wicked witches; but now that you have killed one of them, there is but one Wicked Witch in all the Land of Oz--the one who lives in the West."
Aqui está uma ilustração de 1900 da Bruxa do Norte do livro:
Wikipedia tem a dizer sobre ela:
The Good Witch of the North is a fictional character in the Land of Oz, created by American author L. Frank Baum. She is the elderly and mild-mannered Ruler of the Gillikin Country. Her only significant appearance in Baum's work is in Chapter 2 of The Wonderful Wizard of Oz (1900), in which she introduces Dorothy to Oz and sends her to meet the Wizard, after placing a protective kiss on her forehead. She makes a brief cameo appearance at Princess Ozma's birthday party in The Road to Oz (1909), but is otherwise only mentioned elsewhere in the series.