Jesus was both perfectly divine and perfectly human. He was the Incarnation of God. Mary couldn’t be mother of just part of Him. Your own mother was not just mother of the DNA you recieved from her, was she? Or was she entirely your mother?
Mary was not the mother of the Eternal Holy Trinity. the titles Mother of God, Theotokos or God-bearer does not refer to that. Anyone with basic knowledge of orthodox Christian theology would understand that.
But, since Jesus Christ was the earthly Incarnation of the 2nd Person of the Most Holy Trinity, and because Mary bore Christ in her womb, she is rightly refered to as “Mother of God” or “Theotokos”.
Mary, the Blessed Virgin ("all generation shall call me blessed"), is the Mother of the Man-God, the Person Jesus Christ. As Jesus is True God, and He is one Person, not two, Mary is the Mother of God. She is NOT the origin of God, but she is the mother of the person who is the Man-God, Jesus Christ, who became incarnate through the power of the Holy Ghost.
“Mary was not the mother of the Eternal Holy Trinity.”
I agree.