Enid Blyton's The Folk of the Faraway Tree

Jo, Bessie and Fanny have a visit from snooty friend Connie. Connie won't believe in the Faraway Tree and the magical people who live there - Moon-face, Silky the fairy and Saucepan Man. There's only one way to prove her wrong - together the children climb the tree, and visit some of the lands at the top of it, like the Land of Secrets and the Land of Treats. And after a few adventures, Connie learns to be a nicer person altogether