The lady from Berhampur showed great determination. How did she overcome the final obstacle to offering her khichdi to Sai Baba?

The lady's determination was indeed remarkable. Having traveled from Akola to Shirdi specifically to offer khichdi, she was unwilling to let her vow remain unfulfilled. Chapter 28 explains that on the fifteenth day, she arrived at the mosque to find that Baba was already eating his meal behind a curtain. Normally, no one would dare to go inside at such a time. However, her enthusiasm was so great that she did not remain quiet outside. She disregarded the convention, moved the curtain with her own hand, and made her own entry "by her own authority" to finally offer the khichdi and fulfill her heart's desire.