It is true that the Virgin Mary was the Mother of Jesus, conceiving him in her womb and bearing him for nine months.
However, her motherhood was much more than that, as motherhood is is a term that goes beyond the physical.
Mother of God
St. John Paul II explains the Church's teaching in Mulieris Dignitatem that Mary's motherhood meant that she was not simply the Mother of Jesus, but also the Mother of God:
This truth, which Christian faith has accepted from the beginning, was solemnly defined at the Council of Ephesus (431 A.D.). In opposition to the opinion of Nestorius, who held that Mary was only the mother of the man Jesus, this Council emphasized the essential meaning of the motherhood of the Virgin Mary.
At the moment of the Annunciation, by responding with her "fiat", Mary conceived a man who was the Son of God, of one substance with the Father. Therefore she is truly the Mother of God, because motherhood concerns the whole person, not just the body, nor even just human "nature." In this way the name "Theotókos" -- Mother of God =- became the name proper to the union with God granted to the Virgin Mary.
St. John Paul II highlights the simple fact that "motherhood concerns the whole person," expanding its definition beyond the biological.
It also opens up the possibility of "spiritual motherhood" and how Mary became a Mother we can all turn to in times of need.
Mother of the Church
This spiritual motherhood of the Blessed Virgin Mary expanded her heart to encompass the entire Church, as the Catechism of the Catholic Church explains:
"The Virgin Mary . . . is acknowledged and honored as being truly the Mother of God and of the redeemer. . . . She is 'clearly the mother of the members of Christ' . . . since she has by her charity joined in bringing about the birth of believers in the Church, who are members of its head." "Mary, Mother of Christ, Mother of the Church."
Furthermore, her motherhood did not end when she was assumed into Heaven, but persists until the end of time:
"This motherhood of Mary in the order of grace continues uninterruptedly from the consent which she loyally gave at the Annunciation and which she sustained without wavering beneath the cross, until the eternal fulfillment of all the elect. Taken up to heaven she did not lay aside this saving office but by her manifold intercession continues to bring us the gifts of eternal salvation . . . . Therefore the Blessed Virgin is invoked in the Church under the titles of Advocate, Helper, Benefactress, and Mediatrix."
We can learn from Mary how motherhood is much more than the biological and requires a heart open to God's love, so that a mother can pour that love upon her children, even if those children did not come from her womb.
