Miracles

A woman named Kate claims to have witnessed a miracle. Specifically, she says that within the last year or so she and a few others prayed over a woman who had been born with one leg shorter than another and who had experienced a good bit of resulting pain. As they were praying, Kate saw the woman's leg actually grow to be the same length as the other. Further, the woman reported that her pain was gone. Kate claims that this healing event was a lasting one. Are miracles real? If so, what implications might they have for faith?