Nowhere in the Bible is Mary called the “mother of God,” despite the author’s uses of the term “orthodoxy.”
Mary was a human being, and she found favor with God—God is a triune God: Father, Son and Holy Spirit and is self-existent, has always existed, but not in the flesh until the Holy Spirit came upon her, and the power of the Most High overshadowed her; “and for that reason the holy offspring was called the Son of God, and the Son of the Most High.” (Luke 1:26-35)
The title "Theotokos" (literally "God-bearer," but rendered into English, via Latin, as "mother of God") was part of the early church's grappling with the question of what precisely it meant to say thst Jesus is truly human and truly divine, yet only one divine Person.
To not do violence to Jesus' humanity, you have to admit that that Person is Mary's son and that she is his mother. To not do violence to Jesus' divinity, you have to admit that Mary's son is the incarnate Second Person of the Trinity ... God.