One of the best known and most thoroughly investigated of modern mediums, Leonard was born in Lancashire, England, in 1882, and her development as a medium can be considered to some extent as typical of the experience of gifted psychics generally.
At an early age she was traumatized by events surrounding the sudden death of a friend of the family: no one thought to explain the man's abrupt disappearance, and an impatient housemaid told the child only that he was to be buried "under the earth." The child asked, "Where he can't get out?" and was told, "Of course he can't get out." As if to compensate for the terror this explanation set off, Leonard began to have early-morning visions of the "most beautiful places." When she described her thrilling scenes, however, she was reprimanded; she soon learned to keep them to herself, and they eventually disappeared. In adolescence she discovered spiritualism but was told by her mother that such ideas were "vile and wicked." At the age of 24, spending the night in another town, away from her family, she woke to see a vision of her mother surrounded by a bright light and in apparent good health, although she knew her to be quite sick. When she learned afterward that her mother had died at that moment, her belief in her gifts was confirmed. While attempting a seance with some friends, she succeeded in going into a trance, during which Feda, a young Indian girl who had been married to Leonard's great-great-grand-father, made herself known. Leonard's work with Feda as her control was studied for 40 years. She willingly participated in controlled experiments to ascertain whether her gifts were in fact mediumistic or superbly telepathic, submitting to verifications by detectives and repeated tests with written materials over long periods of time. Investigators failed to conclude one way or another, but Leonard's honesty and attunement to a paranormal force of some sort appeared to be strongly documented.