Jacob Stein writes: Considering this, how frequent are sexual relations between adult Orthodox Jewish men and little girls, with the blessings of the rabbis? Not very. I know of no Jewish bride in modern times who was under 17. In ancient times, my impression is that typically brides were 12 while the grooms were 18. In fact, the Talmud Tractate Kiddushin 41a states “It is prohibited for a father to betroth his daughter in marriage until she matures and declares that she wishes to marry the groom.” Tosafos however does qualify that by saying that in a situation of extreme poverty and economic uncertainty, as was the case for Jews in medieval France, a man may marry off his small daughter if he is afraid that later he will not have the financial means to do so and she will therefore remain a lifelong spinster.
In conclusion, based upon the available documentation, a sexual relationship between an adult man and a little girl, with the consent of the rabbis, seems to have been a rarity which was permitted in some unusual, emergency situations in medieval Europe. Today it is unimaginable.