Thomas Aquinas

“ Further, Augustine says (Ep. ad Dardan.) : "The sanctification, by which we become temples of God, is only of those who are born again." But no one is born again, who was not born previously. Therefore the Blessed Virgin was not sanctified before her birth from the womb.
Objection 3: Further, whoever is sanctified by grace is cleansed from sin, both original and actual. If, therefore, the Blessed Virgin was sanctified before her birth from the womb, it follows that she was then cleansed from original sin. Now nothing but original sin could hinder her from entering the heavenly kingdom. ”

“ Nor are we to believe that any others, not mentioned by Scripture, were sanctified in the womb. For such privileges of grace, which are bestowed on some, outside the common law, are ordered for the salvation of others, according to 1 Cor. 12:7: "The manifestation of the Spirit is given to every man unto profit," which would not result from the sanctification of anyone unless it were made known to the Church. ”

“ God gives to each one according to the purpose for which He has chosen him. And since Christ as man was predestinated and chosen to be "predestinated the Son of God in power . . . of sanctification" (Rom. 1:4) , it was proper to Him to have such a fulness of grace that it overflowed from Him into all, according to Jn. 1:16: "Of His fulness we have all received." Whereas the Blessed Virgin Mary received such a fulness of grace that she was nearest of all to the Author of grace; so that she received within her Him Who is full of all grace ”