This is very subjective stuff, many parts of the world do not think of 14-15 year olds as children and people of that age are expected to work to help the family budget. All four of my grandparents left school and went to work at fourteen, in the sixties minimum school leaving age was fifteen and very many did, a lot of the girls left at Easter if they were fifteen by that time. This is the UK we are talking about, when there were still millions of jobs available !
I do not think it fair to impose the standards of first world countries upon the poorer populations of the world.