Why do the kids think Gloria dump is a witch?

The kids think Gloria Dump is a witch because of her mysterious appearance and the rumors that surround her, particularly her reclusive lifestyle and her home filled with odd objects. They are influenced by local tales and their imaginations, which lead them to view her as a figure of fear and superstition. Additionally, her knowledge of plants and potions contributes to their perception of her as someone with magical abilities. This combination of fear and fascination drives their belief in her as a witch.