The Bible teaches that Mary was a sinner like any of us. She was only used as a chosen vessel through which the Son of God would enter the physical realm. She is not God and should not be worshipped.
Psalm 51:5; Leviticus 12:1-8; Luke 1:38; Luke 1:46-47; Luke 2:21-24; Luke 11:27-28
She was a virgin till Jesus was born, but after that, like any other married woman, she had a regular wife-husband relationship with Joseph and had sons and daughters with him.
Matthew 1:24-25; Mark 3:31-32; Mark 6:3; Acts 1:14
Mary does not intercede for us because she cannot.
1 Timothy 2:5