I do believe that in most cases the parents are the best ones to decide if a child should marry under 18. I got married at 16 to a 19 y/o. When life expectancy was shorter and large families were needed to survive, kids were expected to mature and marry at a much younger age. I read somewhere that after the civil war young girls were marrying older men because so many of the young ones didn't return.
So..I don't necessarily agree with a set age but accept our laws which were probably made because kids were being abused.
All of that said...under no circumstances do I support anyone, man, woman, esp child, being abused in any way, whether cult or family.
That is what these compounded religious cults do. They abuse their own children mentally and emotionally and spiritually until they are old enough to be abused sexually.