I've heard devotees had to be persistent to serve Baba. Is there a story about someone overcoming obstacles to make an offering?

Yes, the path of devotion often required persistence. Chapter 28 recounts the experience of a lady who came to Shirdi specifically to offer khichdi, a vow she made after Baba appeared in her dream. Despite staying in Shirdi for two months, fourteen days passed and she was still unable to make her offering. Unwilling to accept further delays, on the fifteenth day, she approached the mosque at noon. As detailed in Chapter 28, Baba was already eating behind a curtain, a time when no one was allowed inside. Driven by her deep desire, she boldly moved the curtain herself and entered to fulfill her vow, demonstrating remarkable determination.