How old was the Virgin Mary when she gave birth to Jesus?

That's kinda unlikely.

I think the Jews not only traditionally had young marriages, but also tended toward arranged marriages. This pushes the age as youbg as possible while still being of age. Since Jewish men and women have bar (and bat) mitzvahs, around 14 or 15, I'd say that's her likely age.

Undoubtedly you would have believed Saint Clement of Alexandria, who was a saint in the Martyrology of the Roman universal church, and who, in support of the great lie, speaks of the time that some imaginary midwife, who was supposed to be at the birth of Jesus, (Non-biblical) told some woman by the name Salome, that the mother was still a virgin after the birth and that her hymen was still intact, and that this supposed Salome, stuck her finger into the mother’s vagina to check, and her hand immediately withered up, but the baby Jesus reached out and touched her hand and healed it. (All non biblical).

Down to the 17th century, Clement was venerated as a saint. His name was to be found in the Martyrologies, and his feast fell on December 4. But when the Roman Martyrology was revised by Clement VIII (Pope from 1592 to 1605), his name was dropped from the calendar on the advice of his confessor, Cardinal Baronius. Pope Benedict XIV in 1748 maintained his predecessor's decision on the grounds that Clement’s life was little-known; that he had never obtained public cultus in the Church; and that some of his doctrines were, if not erroneous, at least highly ‘suspect.

"ERRONEOUS? HIGHLY SUSPECT?" they certainly got that right, but by the 15th century the false teaching of the so-called virgin birth had become firmly established in the minds of the gullible multitude.

Who cares? So what? What's the point? What does it prove? What does it disprove? What does it change?

Who cares? Not biblical ignoramuses who attack that which is beyond their capacity to comprehend, that's for sure.

The great grandfather of the biblical Jesus was Yehoshua/Jesus III, who was the high priest in Jerusalem from 36 to 23 BC and is believed to have been murdered at the orders of Herod the Great. The sonless Yehoshua, had three daughters, Joanna, Elizabeth and Anna/Hanna.

Knowing that his Zadokian lineage would become extinct unless his ageing daughters were placed with future husbands according to the Torah, he married them off to chosen husbands.

The young Davidian prince Heli, [Alexander Helios III] the son, or adopted son of Mattathias ben Levi, was chosen by Yehoshua/Jesus III the high priest in Jerusalem, as the candidate to marry his daughter Hanna/Anna.

Revealing that the marriage of Mary’s parents was an arranged marriage.

Jehoshua III, the High Priest until 23 BC, is supposed to have died three years before the birth of his granddaughter ‘Mary.’ If it was his death that ended his period as high priest in Jerusalem in the year of 23 BC, this would mean that Mary was born in 20 BC and as Herod the Great died in 4 B. C. two years after the birth of Jesus in 6 B. C., This would make Mary about 14 when she gave birth to Jesus the biological son of her half-brother, Joseph the son of Heli/Alexander Helios. See Luke 3, 23.

IF God thought that was important enough, He would have clearly revealed it.
Why then are you concerned about this?

For those who seek to hear from a True Prophet of God, then go to DiscipleDave(dot)com.
But know this, This last days generation will NOT believe most of the videos that God has revealed to me, which most likely will be you too.

New International Version ZECHARIAH 13, 3; And if anyone still prophesies, their father and mother, to whom they were born, will say to them, ‘You must die, because you have told lies in the LORD’s name.’ Then their own parents will stab the one who prophesies.