You are not following their scenario...Mary is the daughter of God...Mary is the Mother of God...Mary is the wife (bride) of God...Mary has her own throne...
Mary was merely the mother of the male child who was God. She is NOT the mother of God - God is “I AM” and has no parents. When Jesus came to Earth, He humbled Himself and took on the form a servant. Mary is a child of God if she is saved (which is reasonable to presume), same as all other Christians. No Saint (which is what the Bible calls Christians) have a throne in heaven. None other than the Lord has a throne.
It’s the Bible, not any man called priest or pope by other men.