So you admit Mary wasn't born perfect and she needed a Savior...Like the rest of us...
The Catholic and Orthodox churches both have said from the beginning that Mary needed a savior, that her Son is/was her savior. How could she be sinless without a savior? The problem that comes up here is how everyone thinks about the salvific power of God as running along our cosmic timeline. It doesnt. God exists outside of time, Mary was saved by her Son's sacrifice, her Son, who is God
The "splendor of an entirely unique holiness" by which Mary is "enriched from the first instant of her conception" comes wholly from Christ: she is "redeemed, in a more exalted fashion, by reason of the merits of her Son".
Mary, though considered unique among saints, was still created by God, by her Son
In short, Mary needed a savior, like all created things, but she received her salvation through the merits of her Son, before time.
Not attempting to speak for the Orthodox here, but it is Catholic dogma that Mary needed a Savior.
And also that she had one.