Sarah Hershberger, who recently turned 11, her parents and the couple's baby daughter now are in hiding in the United States, Isaac Keim said.
The Hershbergers have been fighting doctors at Akron's Children's Hospital in court for months after the parents decided to halt the treatments because they were making Sarah sick.
Doctors say her leukemia is treatable, but say she will die within a year without chemotherapy. The hospital sought to force treatment after the family opted to try natural medicines, such as herbs and vitamins.
The family has appealed the court decision that gave an attorney who's also a registered nurse limited guardianship over Sarah. They don't plan on returning until the ruling is reversed.
"What kind of gift would that be, if we could get this resolved and they can come back home without a fear of being in contempt of court or having their child snatched away," Keim said. "We're praying every day that this thing can be resolved and get their lives back together."
The Hershberger's five other children are staying with community members near their farm outside the village of Spencer.
Keim said that CT scans and blood tests show that the natural treatments are working. He said she is cancer-free.
"She's a vibrant, healthy girl," Keim said.
The Amish are deeply religious and shun many facets of modern life, but they don't reject modern medicine.
Andy Hershberger said this past summer that the family agreed to begin two years of chemotherapy for Sarah last spring but stopped treatment in June because it was making her extremely sick.
Officials at Akron's Children's Hospital have said they are morally and legally obligated to make sure the girl receives proper care. They said the girl's illness, lymphoblastic lymphoma, is an aggressive form of non-Hodgkin lymphoma, but there is a high survival rate with treatment.