Going by your definition of child,the father of nation Gandhi should first be prosectued for child marriage,but doing so would be ridiculuos because the early genrations even if its just 100 yrs ago had a different level of biological and mental maturity. Now dont bluff this is a child marraige,Gandhi had his first son just 3 years of this marriage
Check the age of kasturbha Gandhi history on University of California, Los Angeles
..Kasturba Gandhi, known affectionately as Ba, was married to Mohandas Gandhi in 1882 when she was but ten years old..
I have repeated ad infinitum with proof that 9 yeard olf today has a different mental and biological characteristics.Before debating me, confirm at what age your previous generations for example our gradn mother s used to get married..It is not 21,it is not 18,it is not 16,it is much before 14.. and this is just one genaration above..