Kids may think differently from adults. Perhaps, their minds tend to wander, and they also have more time to think and imagine several things, probably from what they see on television or what they read in books.
It is quite hard to distinguish if kids are making it up when they say something like “someone is standing next to you”, but you’re sure that there is no one beside you. There are also those who have experienced unexpected encounters like hearing the child sing in a different language, which none in the family uses.
Enjoy reading these stories, but good luck ever sleeping again.