Noah and Jacob, for example, are described one as righteous another as perfect. By reason we know that infants are likewise free form personal sin.
It is true that all righteousness and perfection, of Mary or anyone else, is a gift from God, just like the Council of Orange teaches.
It's been fascinating these past few years to read here how RCs deny the stain of original sin. It wasn't always that way.
Whether it is Noah or Jacob or Job or John or Paul or you or me or our infant children, all righteousness is the righteousness of Christ.
"For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him." -- 2 Corinthians 5:21"I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me." -- Galatians 2:20