Mary is the mother of Jesus. We agree here.
But because She is the Mother of Jesus who is God the second person assuming humanity through Mary by the incarnation. She is also the Mother of God. Because even though she is the Mother of the humanity of Jesus. His nature is inseparable from His person. And his person is by incarnation God and Man.
The term *mother of God* is a man-made construct which is never used by God in the Scripture He breathed out.
The term *mother of Jesus* is what is used in Scripture.
Using the term the Holy Spirit insired keeps people from confusion and deception about who Mary is that using man-made constructs will lead to.
So, you believe God has a beginning and must be born to exist?
Hoss