The petitioner shall prove by a preponderance of evidence the facts alleged in the adoption petition and that the adoption is in the best interests of the child.
Minn. R. Adop. P. 44.04
The Indian Child Welfare Act, 25 U.S.C. § 1901, et. seq., does not state a standard of proof for adoption matters as it does for foster care and termination of parental rights matters.