(Mike Simons/Tulsa World via AP, File) In this Aug. 6, 2013, file photo, Veronica, 3, a child at the center of an international adoption dispute at the time, smiles in a bathroom of the Cherokee Nation Jack Brown Center in Tahlequah, Okla. A federal law that gives preference to Native American families in child welfare proceedings involving Native children is facing a significant legal challenge. In 2013, the U.S. Supreme Court ruled the law didn’t apply in a South Carolina case involving Veronica because her Cherokee father was absent from part of her life.