The way this story reads, authorities believe it could be rape. In the U.S., at a minimum, it’s statutory rape.
The girl is saying they were in a ‘loving relationship.’ The authorities think she is confused and don’t necessarily believe she is telling the truth. It is not stated directly in the article, but they probably believe she is mentally impaired.
That would lead one to conclude that if she consented and was in a ‘loving relationship’ with the baby’s father (who has now fled), and able to make judgments, by Mexican law it is not rape. The authorities are trying to find him and figure it out.
The father should be shot.
The girl is young and impressionable and has been brainwashed at a minimum into thinking this was okay.