One needs to review the literature and references very well. No matter which theology you are having, Holy books don't endorse child marriage. When it comes to survival many forbidden things are even made choices but on conditions of only survival and in this case of marriage I don't think that any book will reflect such a point.
About marriage, Islam clearly indicates the terms and conditions and puberty is the first one, one is not allowed to have any relationships when the partner hasn't gained maturity(consent is crucial in all cases) so why you will say that religion authorizes this injustice of child marriage from either gender??? @nevies If you want to glance follow the link
. But child marriages are non-supportive and unlawful everywhere. It's a ruthlessness to do so or blame anyone for this.