Who is ranghild Hansen in the book the witches?

In the book "The Witches" by Roald Dahl, Ranghild Hansen is a character who is a member of the Society for the Prevention of Cruelty to Children. She is a key figure in the story as she helps the protagonist, a young boy, in his mission to stop the witches' evil plans. Ranghild Hansen is portrayed as a brave and resourceful individual who plays a crucial role in the plot's development.