Mary has no such title. She is never referred to as such in the Bible. There is no reference that the Disciples considered her as any person worthy of worship or by title. No commandment to treat her any different than anybody elses mother. Again, Jesus is the focus not Mary, not the Pope and not any Church rituals.
First, that is what she is, for Jesus is God. Second, Luke 1:43. Third, the Holy Scripture is not a table of ranks and titles.
The Holy Spirit saw fit to call Mary, *the mother of Jesus*.
Apparently, Catholics think that what the Holy Spirit does isn't good enough.
John 2:1 On the third day there was a wedding at Cana in Galilee, and the mother of Jesus was there.
John 2:3 When the wine ran out, the mother of Jesus said to him, They have no wine.
Acts 1:14 All these with one accord were devoting themselves to prayer, together with the women and Mary the mother of Jesus, and his brothers.
The Holy Spirit, in Scripture, is clear in calling her *mother of Jesus* not *mother of God*. The phrase *mother of God* is not found ANYWHERE.