Could 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 for Sai Baba's darshan with a letter from Kelkar. She had made a firm resolution in her mind to fast for three days while sitting at Baba's feet. However, Sai Baba, being the 'inner witness' who knows everything in a person's heart, was already aware of her plan. He had previously made a prediction to Dada Kelkar during the Shimga (Holi) festival, asking rhetorically how he could let his children remain hungry. True to his word, Mrs. Gokhale arrived the very next day, and Baba's foreknowledge and disapproval of her intended penance were made clear.