As Catholics, We do not believe that Mary created the divine person of Jesus, who “was with God in the beginning”; rather we believe that Mary conceived by the power of the Holy Spirit, and through her, Jesus Christ, the second person of the Blessed Trinity entered this world taking the nature Man. Hence, in the Second Person of the Blessed Trinity is united both a divine and a human nature.
Hence the church professes:
“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”(Lk 1:26-38). 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” (Theotokos)”. – (CCC, No. 495)
The Universal Church Celebrates the Solemnity of Mary, Mother of God on the First day of every year (1st January).