Wrong. Notice the "us" in the verse...plural...not "she".
This does not connote just Mary, but all believers. John in Revelation says Christ was crucified from the foundation of the Earth; all believers were actually sanctifed before time began in a way.
However, all created humankind are sinners while living in Adam's fallen world in time. The scripture you pointed out does NOT delineate Mary as special.
The very fact that some verses of Scripture says that none are sinless, none are "just," none are holy but God; and others say, for instance, that Joseph was "a just man" and God chose "us" to be holy and blameless before Him, means, at the very least, that we need to interpret these Scriptures in a wide and authoritative context.
Which is just what you (or I) who do proof-texting by one-liners cannot do.
Catholics and Orthodox --- and others, if they wish to --- do well to pay close attention to how the earliest disciples and successors of the Apostles came to understand and interpret these texts. This is called "Sacred Tradition,"-- its study comprises Patristics (the study of the Fathers) and it is of particular importance to Catholic and Orthodox theology; many Protestants study and benefit from it as well.
Be careful, though. The further back you go, back to the Third, the Second, the First Christian centuries ---Clement of Rome, Mathetes, Polycarp, Ignatius of Antioch, Barnabas, Papias, Justin Martyr, Irenaeus, Andrew of Crete --- the more Catholic and Orthodox your thinking will become.
Fair warning, my FReeper friends.