When I interviewed pilgrims on P’u-t’o Island in March 1987, I asked if they knew of any stories about Kuan-yin’s response either to their own prayer or somebody else’s.
Invariably the reply was affirmative. For example, a young woman of twenty-four came with her mother, a retired nurse of forty-nine, from Shanghai to fulfill a vow (huan-yüan).
Two years earlier, the mother had developed cancer of the intestines. When she was operated on, the cancer was very advanced and had spread. So the doctor sewed her up and predicted that she would die soon.
The mother prayed to Kuan-yin for a whole year and vowed that if she should survive, she would come to P’u-t’o to give thanks. Two years had passed and she was well, so the mother and daughter traveled to the island.
~ From “Kuan-Yin” book by Chün-fang Yü, page 152