Can you tell me about the woman who came to Shirdi intending to fast and what happened?

Certainly. Chapter 32 recounts the story of a woman named Mrs. Gokhale who came to Shirdi with a letter from Dada Kelkar. She had made a firm resolution to fast for three days while sitting at Sai Baba's feet. However, this was in direct opposition to Baba's teachings. Unbeknownst to her, Baba was already aware of her plan, having prophetically told Kelkar, "How can I let them [my children] remain so?" When Mrs. Gokhale arrived and went for darshan, Baba, being the "inner witness," knew everything in her heart. This incident illustrates both Baba's omniscience and his staunch principle that one must eat before attempting to find God.