Indeed, and Jesus did not sin. You seem to imply that a child has sinned just by being born. Can you show scripture for that, please?
I never claimed or implied that a child sins by being born. However, as Paul teaches in Romans 5, and as the Church has always taught, in opposition to Pelagian heretics, babies are born with original sin, on account of Adam's sin. If Christ had been born with original sin, then Christ Himself would have needed redemption from sin. But the Redeemer cannot Himself need Redemption. Therefore, Christ could not have been born with original sin. Hence, two things were necessary: (1) Christ had to be conceived by the Holy Ghost (Joseph could not have Christ's biological father) and (2) Mary had to be sinless, so as to contribute sinless flesh to the incarnate Christ, to be woven together in her womb.
-A8