Holy Scripture AND Holy Tradition.
What did the apostles say about Mary? It’s not all in Scripture. Read the Early Church Fathers.
Was every single thing that the apostles said, and every single word written about them by later scribes, considered by your church to be Holy-Spirit-inspired, inerrant and infallible?
Tradition? Do you remember the Pharisees they put tradition above truth. The bible says very little about Mary, we know she looked to Christ for her salvation, she was a servant of the God most high. She was a sinner like us. This is what scripture tells us. I do understand the mental gymnastics one goes through to validate this belief.
The church fathers were not holy men who spoke by inspiration of God...
If any one of them claimed Mary was sinless, they lied...God says ALL have sinned...