Answer by taking a quote from the following article:

Aimee Semple McPherson (Aimee, in the original French; October 9, 1890 - September 27, 1944), also known as Sister Aimee or simply Sister, was a Canadian-American Pentecostal evangelist and media celebrity in the 1920s and 1930s, famous for founding the Foursquare Church. McPherson has been noted as a pioneer in the use of modern media, because she used radio to draw on the growing appeal of popular entertainment in North America and incorporated other forms into her weekly sermons at Angelus Temple, one of the first megachurches. In her time she was the most publicized Christian evangelist, surpassing Billy Sunday and her other predecessors. She conducted public faith healing demonstrations before large crowds; testimonies conveyed tens of thousands of people healed.

McPherson's ability to draw crowds was also greatly assisted by her apparently successful faith healing presentations. According to Nancy Barr Mavity, an early McPherson biographer, almost by accident, the evangelist discovered when she laid hands on sick or injured persons, they got well. Mavity further wrote, describing the healing power "beyond her conscience [sic] control" and "profoundly troubling" however a phenomenon familiar to the psychiatrist although "none the less [sic] mysterious."  During a 1916 revival meeting in Corona, Long Island, New York, a young woman in the advanced stages of rheumatoid arthritis was brought to the altar by friends. McPherson would have preferred to pray with her privately. However, the woman insisted upon immediate prayer. McPherson laid hands on her and prayed. Before the gathered parishioners, the woman walked out of the church without crutches. McPherson's reputation as a faith healer rapidly became known and the sick and injured people came to her by the tens of thousands.  The Faith Healing Ministry of Aimee Semple McPherson was extensively written about in the news media and was a large part of her early career legacy. No one has ever been credited by secular witnesses with anywhere near the numbers of faith healings attributed to McPherson, especially during the years 1919 to 1922. Over time, though, she almost withdrew from the faith-healing aspect of her services, since it was overwhelming other areas of her ministry. Scheduled weekly and monthly healing sessions nevertheless remained highly popular with the public until her death in 1944.

What happened after she discovered this?
During a 1916 revival meeting in Corona, Long Island, New York, a young woman in the advanced stages of rheumatoid arthritis was brought to the altar by friends.