Mary’s hymen must have been miraculously left intact, because as the poster above said,
Joseph Cardinal Ratzinger explains in his book Daughter Zion:
“The cavalier divorce of “biology” and theology omits precisely man from consideration; it becomes a self-contradiction insofar as the initial, essential point of the whole matter lies precisely in the affirmation that in all that concerns man the biological is also human and especially in what concerns the divinely-human nothing is “merely biological.” Banishment of the corporeal, or sexual, into pure biology, all the talk about the “merely biological,” is consequently the exact opposite of what faith intends. For faith tells us of the spirituality of the biological as well as the corporeality of the spiritual and divine. On this point the choice is between all or nothing. The attempt to preserve a spiritual, distilled remainder after the biological element has been eliminated denies the very spiritual reality which is the principal concern of the faith in the God become flesh.”
We cannot seperate the physical symbolism of Mary’s virginity from her spiritual virginity.
As for suffering pain in childbirth, I would on the other had disagree with early Fathers and say she did.
As asked, why should she, just because she was free from original sin, not suffer if Jesus still did?
Although free from all spiritual stain of original sin, the fleshy bodies of Jesus and Mary were still descended from Adam and still had the effects of original sin…that is why they were MORTAL. That is why Jesus worked by the sweat of his brow. That is why they could suffer hunger, thirst, fatigue, sorrow, and pain.
So I would say it would be oddly inconsistant if she did not suffer pain in childbirth if she still suffered everything else. And the Woman in Revelations does cry out in her birthing pains.
The birth may have been miraculously bloodless, with the hymen miraculously stretched, but unless that is what caused the painlessness…I’d say there was still pain. Unless the absence of pain was just a result of the miraculous method of preservation of virginity…but I doubt there was a special exemption specifically to preserve from pain.