The story goes that if you’re in a bathroom or closed room with a mirror and you spin around three times and the lights are off and the door is closed. If you spin around saying Bloody Mary three times and you look in the mirror, you will see Bloody Mary and probably die.
My informant heard this story as a kid from a friend. She was told this story in an afterschool program in elementary school. It was around 4 pm, still during daylight hours, but it still freaked her out and made it so that she would not want to go to the bathroom alone. She did believe in Bloody Mary as a kid because it was based off of a real person, so it gives the feeling that it is real, which makes it creepy.
Bloody Mary seems to be a creepy story spread mostly among young children to pass the time. It is not really clear why the story persists even after many years since the historical origin has passed. My only assumption for the persistence of this tale among children is that it is both a right of passage and as a show of maturity.