Is this "fairy" a figurative meaning for an angel-like person? Is it a common expression or the writer's unique made-up one?
ex)...The carpark next to our library uses a pay-and-display system... A couple of months ago, a woman offered me her ticket as she was leaving; the ticket still had one hour remaining. What a bonus; I didn't have to look for some spare coins. On the next visit, I noticed that the parking fairy had left a ticket with about 45 minutes remaining in the slot of the machine for some lucky person to use....
In this example, it's the writers own creation and it means that some generous person left behind something of value for another person to make use of.
John