No, gouda isn't green.
Why do you wish me to hypothesize about something which cannot be?
Cannot be?? Claiming that it did not happen is one thing, but now you're claiming that it could not happen? God created sinless human beings when he created Adam and Eve. Did he lose that ability at some point?
Putting limits on God's grace and sovereignty is a really, really bad and un-Protestant idea. God can raise up sinless human beings by the millions out of mushrooms, if he wants to. Cannot be? I can't believe you said that.
This sounds like one of those "can God make a rock so big He can't move it" types of arguments.
Mary was not created ex nihilo, as was Adam (and by extension Eve). She had both a human mother and father. Sin comes generationally through the father. Unless Mary's father were also born sinless, she could not be. And so on.
Since Jesus had no earthly father, original sin was not passed to Him. He was the only person born sinless. He was absolutely unique in that regard, being without original or actual sin.
Of Jesus (not Mary) it is said, "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him."