parking fairy

[keannu]

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....

[JohnParis]

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