Here are the materials in Nielson v. Ketchum:
Cherokee Nation Appellee Brief
The summary of the case from the opinion:
This case concerns the application of the Indian Child Welfare Act (ICWA), 25 U.S.C. §§ 1901-1963, which, among other things, imposes a period of ten days before a parent can consent to the termination of her parenting rights over an “Indian child.” The day after giving birth to C.D.K., Petitioner-Appellee Britney Jane Little Dove Nielson appeared in state court in Utah to relinquish her parenting rights and consent to the adoption of her son by Respondents-Appellants Sunny and Joshua Ketchum. The court determined that although Nielson’s mother was a registered member of the Cherokee Nation, Nielson was not, and consequently the court approved the adoption without applying the procedural safeguards of the ICWA.
Later, Nielson filed suit in federal district court, claiming that C.D.K. was an Indian child at the time of the adoption and hence the ICWA’s ten-day waiting period should have applied. Even though she was not herself a member of the Cherokee Nation, Nielson pointed to a law passed by the Cherokee Nation establishing automatic temporary Cherokee citizenship for any newborn who is the direct descendant of a Cherokee listed on the Dawes Commission Rolls. The district court agreed that this act established tribal citizenship for C.D.K., and it invalidated Nielson’s relinquishment of parental rights, leaving the matter of custody of C.D.K. for the Utah state courts. We exercise jurisdiction pursuant to 28 U.S.C. § 1291 and reverse on the grounds that C.D.K. was not a member of the Cherokee Nation for ICWA purposes at the time of the adoption.
Turtle Talk 
Tribal right to define membership is preservation. The resource of preservation (by ICWA own language) is the most precious resource of tribal children.