The Guardian, Home to Hickory Hollow Series by Beverley Lewis and published by Bethany House Publishers.
When schoolteacher Jodi Winfield goes for a morning run, the last thing she expects is to find a disheveled little girl all alone on the side of the Pennsylvania road, clad only in her undergarments, her chubby cheeks streaked with tears. Jodi takes the preschooler home with her, intending to find out where she belongs. But Jodi is mystified when no one seems to know of a missing child, and the girl herself is no help, since she can't speak a word of English. It's as if the child appeared out of nowhere.
As the days pass, Jodi becomes increasingly attached to the mysterious girl, yet she is no closer to learning her identity. Then an unexpected opportunity brings Jodi to Hickory Hollow--and into the cloistered world of the Lancaster Old Order Amish. Might the answers lie there?