The titles for Mary are really quite appropriate: she was blessed (as declared by the angel, Gabriel); she was a virgin; and she was the mother of God because Jesus is incarnate of God, which was acknowledged by Elizabeth. Some people may fear that exalting St. Mary implies that she comes before God or is on the same level as God. The fact that she was chosen by God to mother of the Messiah shows us that Mary was, in fact, exalted above all women by God himself. By the way, Catholic Christians do not pray TO Mary; we ask that she intercede on our behalf, just as many Protestant Christians ask friends, and even Facebook strangers, to offer prayers on their behalf.