The Christmas Octave concludes with the occasion of the Solemnity of Mary, the Mother of God. Whenever we venerate Our Lady as the Mother of God, we simultaneously claim her to be our mother.
Even though Mary was venerated as the Mother of God from the earliest days of the Church, the Feast was not established until the 4th Century.
In the Catechism of the Catholic Church we read . . .
Mary, Mother of God - Catechism of the Catholic Church 495
Called in the Gospels "the Mother of Jesus," Mary is acclaimed by Elizabeth, at the prompting of the Spirit and even before the birth of her son, as "the mother of my Lord." In fact, the One whom she conceived as man by the Holy Spirit, who truly became her Son according to the flesh, was none other than the Father's eternal Son, the second person of the Holy Trinity. Hence the Church confesses that Mary is truly "Mother of God".
Mary, Mother of God, pray for us.