Slow down, Tony!
Adam and Eve were created (not conceived) without sin. But even being created (or conceived) without sin, one can still have the capacity to sin. Adam and Eve did sin, and fell, but were redeemed.
Jesus is God and man. Jesus was not “created”. By the fact that He is God, Jesus is sinless from the start. As a man, he was ‘tempted’ by sin to the degree any of us are (human nature) but freely chose–as man–to remain free of all sin. This state, by the way, is what humanity was meant to be–capable of sin by free will, yet freely choosing to be without sin in order to please almighty God.
Mary is a creature, conceived without sin by the grace of God. (The only one–that is why her title is “immaculate conception”). Again, fully human, she chose to remain sinless to glorify God.
Now, John was by tradition conceived in sin but when greeted by Mary, the infant Jesus in her womb filled John (in Elizabeth’s womb) with the Spirit. Therefore John, though conceived in sin, was born without sin. However, this does not mean that he never had personal sin in his life; the Church makes no pronouncement on this.
As to Elizabeth, she was greeted and she was filled with the Spirit. Being filled with the Spirit had the same effect on her that it does on us–it opens us to God so long as we accept it and remain free from grave sin–but the Spirit will leave us if we commit grave sin. So yes, Elizabeth was without “grave” sin at the time she was greeted, since only those without grave sin may receive the Holy Spirit. But she was most likely, as we all are, in venial sin–if not just then, at some other time. Since she is a saint, we know that she is in heaven so even if she had any venial sins they have been remitted, otherwise she would still be in purgatory.
OK?