**Catholics can “hold” anything they want. If it doesn’t agree with or can’t be found in scripture I’m not going to risk my eternal future on what “Catholics hold”.**
But this IS in Scripture. Luke 1:25 and onward!
No it’s not.
Luke 1:28 And the angel came in unto her, and said, Hail, thou that art highly favoured, the Lord is with thee: blessed art thou among women.
First of all Mary surely didn’t realize she was sinless.
Luke 1:29 And when she saw him, she was troubled at his saying, and cast in her mind what manner of salutation this should be.
How could anyone think that a person who is sinless doesn’t know it and others around that person wouldn’t have noticed?
Kecharitomene is a derivative of the word charitoo which we can find the meaning of here. [http://www.biblestudytools.com/search/?q=charitoo&rc=LEX&rc2=LEX+GRK&ps=10&s=References]
Charitoo
to make graceful charming, lovely, agreeable to peruse with grace, compass with favour to honour with blessings
This has been debated over and over and not once can anyone show that kecharitomene ever means sinless. On the other hand let’s look at words that do mean sinless. [http://www.biblestudytools.com/search/?q=sinless&rc=LEX&rc2=LEX+GRK&ps=10&s=References]
Anamartetos
sinless of one who has not sinned of one who cannot sin
Not once used to or about Mary.
Pluno
to wash: with reference to clothing use figuratively of those who by faith so appropriate the results of Christ's expiation as to be regarded by God as pure and sinless
Used about all true believers.
Anamartetos
sinless of one who has not sinned of one who cannot sin
Again, never used about or to Mary.
Hagion
reverend, worthy of veneration of things which on account of some connection with God possess a certain distinction and claim to reverence, as places sacred to God which are not to be profaned of persons whose services God employs, for example, apostles set apart for God, to be as it were, exclusively his services and offerings prepared for God with solemn rite, pure, clean in a moral sense, pure sinless upright holy
In Ephesians 1:6 we can see that God has granted every true believer with grace.
Ephesians 1:6 To the praise of the glory of his grace, wherein he hath made us accepted in the beloved.
Luke 1:28 is rightly translated “highly favored”. To try to make that verse somehow infer that Mary was sinless is deceitful.