Bloody Mary remastered

As the legend goes, Bloody Mary is easy to summon. You enter a darkened room with a lit candle look into a mirror, looking deep into your own eyes while chanting chant her name “Bloody Mary, Bloody Mary, Bloody Mary, as you speak her name for the 3rd time your eyes will go black and when you vision returns  you’ll be entranced with the rather shocking image of Mary’s reflection in the mirror behind you dripping in blood of her victims.  We have all heard it... But who was the REAL bloody Mary