I don’t think this is true - at least not in the Hebrew Bible (I don’t know much about the Greek/Christian parts). What verse/ passage are you thinking of?
Fourth book of the Torah says that the army has to kill women who have known a man but to keep the little girls (women children) for themselves. Here’s some commentary about it:
The little ones — The object of the command to kill every male was to exterminate the whole nation, the cup of whose iniquity was full. For the righteousness of the mode see Joshua 6:21, note. Every woman who might possibly have been engaged in the licentious worship of Peor was to share the fate of the male children, to preserve Israel from all taint of that abomination. The pure maidens could be incorporated into Israel without peril to the national religion. Joshua 6:23-25, notes. They could not be treated as concubines, since the law against fornication was in full force, (Deuteronomy 22:25-29,) but they could be lawfully married to their captors (Deuteronomy 21:10-14).
Well, that’s the difference. This is just Daniel Whedon’s personal interpretation. It’s not included in the list above because those are all explicit - not just one person’s interpretation. Obviously a commentary is subjective by nature. Why open up a solid argument to debate by introducing a lower quality argument based on a subjective opinion?
I think they’re thinking of Mary and Joseph (Miriam and Yusef). The ages are tradition not scripture iirc. But yes, she was 14 but it was closer to an engagement until she was old enough to move out of her parents’ house. Which also is fucked up, but like in terms of ancient pedophilia? It’s on the low end.