Mary Sibley

https://minerdescent.files.wordpress.com/2012/04/thomas-cooper-11.j...

From http://newenglandfolklore.blogspot.com/2014/12/the-true-story-of-ma...

The real Mary Sibley played a small but significant role in the actual Salem witch hunt. Mary and her husband Samuel (who was not particularly wealthy or influential) were neighbors of Reverend Samuel Parris. During the winter of 1691 - 1692, Reverend Parris's daughter Betty and her cousin Abigail Williams had been acting strangely. They had made been making odd noises, moving in unusual ways, and complaining of mysterious pains. The local physician thought it might be witchcraft. Reverend Parris and his wife tried to treat the girls' ailments through prayer.
On February 25, 1692, Reverend and Mrs. Parris left Salem to hear a minister speak in another town. Mary Sibley came over to the Parris house and told the reverend's slaves, Tituba Indian and her husband John Indian, to make a cake from the girls' urine and rye flour. Following Mary's instructions, the slaves baked the cake and then fed it to a dog. Mary, Tituba and John then watched the dog to see if it acted strangely.
This type of cake was known as a witch cake, and was method for diagnosing witchcraft. If the girls really had witchcraft in their body, it should also be in their urine. If the dog acted strangely after eating their urine it would be proof the girls were indeed bewitched.
History does not record how the dog reacted, but we do know how Reverend Parris acted. He was furious. All magic was considered evil magic, and he believed Mary Sibley's benign attempt to help the girls had opened the door to greater evil. He may have been right, since after witnessing Mary's magic the two girls began to actually see human forms tormenting them. Previously they had just suffered vague physical maladies. It seems likely that her actions strongly suggested to Betty and Abigail that they were bewitched, and they began to act accordingly from that point on.
Reverend Parris gave Mary Sibley a stern private lecture, and she publicly and tearfully confessed her errors to the Salem Village congregation on March 25, 1692.
Mary fades from history at this point and didn't play any further role in the Salem witch trials.  However, some writers have suggested that her witch cake was the incident that really kicked off the witch craze. They speculate that Betty and Abigail might have stopped their odd behavior if Mary hadn't asked Tituba and John to bake the witch cake.