This book was written for a special girl that had a scary dream about a talking spider. To her it is very scary, as a spider should not be talking, or have a reason to talk to her. Why would a spider even talk to her? She is only five.
So her dream is actually the end result of the spider's story. When we read the spider's story we will learn exactly when and why the girl thought she was having a dream, and in actuality she was not.
She was part of the spider's journey in life and in finding happiness, which the spider found with the little girl.