It does not follow that since Mary is Jesus mother, that she is the mother of every Christian.
It does if God is our Father (Matthew 6:9) and Jesus is God's Son (Matthew 3:17) and we are God's children (John 1:12-13) and Jesus is our brother (Hebrews 2:10-13).
It does not follow.
It is not Biblical and never found in Scripture.
Jesus had a human mother.
We have different human mothers.