“Mary is not the mother of the Trinity, nor is she the mother of God the Father or God the Holy Spirit. She is, however, the mother of Jesus, who is God the Son, made man.”
What I’ve been trying to say.
Nothing more, nothing less.
Hoss
Remember, the Christian belief (not just Catholic!) is that Jesus is one Divine Person, and His two natures are united in this one Person. Mary became the mother of that Person at the moment of the Incarnation. She is not merely the mother of His human nature, or even worse, the mother of merely His body. She is His mother, and since He is God, she is the Mother of God.