Could not tell you, I’m AG, and believe in the virgin birth, knowing Joseph was much older than Mary as he was already a master carpenter. Probably about 30 to her 12-13. And the angel who told him not to be afraid to take her to wife also told him to refrain from touching her until after Jesus’s birth. Scripture prophecy had to be fulfilled of virgin birth.
Except there is no reliable, objective source for what were the ages of Mary and Joseph. I completely accept the virgin birth of Jesus Christ. It was, after all, one of the major prophecies concerning the true Messiah:
Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel. (Isaiah 7:14)
That is why, when Mary was found to be with child before she and Joseph consummated their marriage, he sought to quietly put her away/divorce her since she could be executed for adultery if it was found out. He "moved up" the actual taking her to be his wife after the angel appeared to him in a dream explaining what had happened. And, yes, he did not "consummate" their marriage until after she had given birth to Jesus (He knew her not till she had brought forth her firstborn son: and he called his name Jesus. (Matt. 1:25)).