God the Son, the Second Person of the Trinity, the Word, became flesh in the womb of Mary—taking his flesh from her body. Because he is ONE PERSON, Mary became at that instant the Mother of God.
In that instant, Mary became the mother of JESUS.
GOD does not have a mother, nor beginning nor end.
Saying that God has a mother makes Him a created being, elevating Mary to a position above God in many respects.
Saying that she is the mother of Jesus, does not led to the theological error or unwarranted exaltation of Mary that is the fruit of messing with God given titles.
The Holy Spirit in Scripture NEVER referred to her as *mother of God*, but rather *mother of Jesus* which is who she was.