Don't trust me completely with this but I think it started when spanish fighters came to mexico and brought it there. A quinceanara is a celebration for girls who turn 15 which is considered adulthood.
I don’t know completely, so- but a quinceñera is the celebration of when a girl turns 15, which in the culture means that she is young lady/woman. Given the situation I think it would mean that girls would now be old enough to be married off.
