Whether Mary is the mother of God is a pointless discussion. The Bible makes no reference to this concept perhaps because we are incapable of really understanding the relationship between the Father, Son, and Holy Spirit. Having a thorough understanding of the Bible is difficult enough without adding man created concepts to confuse things.
Incorrect.
"And whence is this to me, that the mother of my Lord should come to me?" Luke 1:43
"And the angel answering, said to her: The Holy Ghost shall come upon thee, and the power of the most High shall overshadow thee. And therefore also the Holy which shall be born of thee shall be called the Son of God." Luke 1:35