As dual nationals, wouldn’t they be welcome in Mexico? Problem solved! Next problem, please...
They would be welcome in Mexico. They apparently have a father who wants them in Mexico. The problem (according to the story) is that the State of North Carolina is not letting them go to Mexico, and is distributing them to its own agents (”foster parents”) and planning to put them up for adoption to strangers instead of letting them go to their father. Apparently, there is not even an allegation of child abuse. Seriously ... on a basic human level, this is just sick.