Foreign Born Derivative Citizenship

Not me:

Foreign born (Vietnam) given up for adoption in 1975 to the US. Was adopted in 1978, as a minor. Was not naturalized, apparently an common oversight.

Anyway, this person is attempting to apply for a Passport and/or N600 Certificate of Citizenship, thru derivative citizenship via their US citizen adoptive parents.

Question, will their full and final adoption court order be sufficient to satisfy the requirement: "Evidence that you were in the legal and physical custody of your U.S. citizen parent(s)"