Maybe it's the parents or grandparents of the children in the Sandy Creek area. They make up these stories based on their own experiences around the creek, like the time they went for a picnic by the creek and saw a deer drinking water. They add a bit of creativity and turn it into a bedtime story.
They could be about all sorts of things. Maybe they're stories of the adventures that happen around Sandy Creek. It could involve the animals that live there, like the squirrels that scurry up the trees or the birds that sing in the bushes.
I'm not sure who Sandy specifically is without more context. She could be an ordinary person with an interesting life story, or perhaps a character in a fictional work that has been made into an audio story.