I heard Udi can help with severe weakness. Is there a story about a child who couldn't walk being cured by it?

Indeed, a footnote in chapter 33 of the Sai Satcharita recounts a powerful story about a child's healing. A gentleman named Khimji Lalji Joshi had a daughter who was ill for a long time and became so weak that her limbs were like twigs and she could not walk. Her mother first brought some Udi which provided immediate relief. They then took the girl to Shirdi, where she was carried to Baba. As mentioned in chapter 33, Maharaj applied Udi to her and blessed her. Miraculously, in just two to four days, she started walking on her own feet. When she still had some trouble getting up, Baba gave her a fruit to eat, which completely removed that difficulty as well.