Part 4 will be posted shortly, ping!
Whooops! That word "full" is no where contained within the meaning of that word. the verb tenses only say that the grace given was fully complete and was done in the past and is still completed. That does NOT mean she was completely "full" of grace. Only that the grace she was given was completed. If the Holy Spirit would have wanted to indicate that she was "full of grace" He would have done it like He did in the case of Jesus and Stephen by using the Greek word plérés as He did for Stephen.
Acts 6:8 Now Stephen, a man full (plérés of God's grace and power, performed great wonders and signs among the people.
The Holy Spirit clearly did not indicate that Mary was "full of grace" as He did Stephen. Mary was simply given grace all we all are and it was completed and continues just as it does for all believers.
If the Catholic Church wants to assign sinlessness to Mary for being "full of grace" (which is in error) then surely they must also assign sinlessness to Stephen as well.