A book set in the Middle East, a sister is healed by Jesus, it has the word Wheel in the title

I read this book at some point in middle school, so it was published sometime before 2010, but it looked older than that. The children are orphaned and the sister has something wrong with her, so the brother goes on an adventure to find a healer for her. I think the title is something like On Fortune’s Wheel, but that could be very wrong. This is bugging me so bad, I want to get it and reread it! Please help!

Having a sister healed reminds me of The Bronze Bow by Elizabeth Speare. It was a Newberry winner so stayed easily available. The book is from the brother's perspective. Daniel and Leah are their names.