62 This maternity of Mary in the order of grace began with the consent which she gave in faith at the Annunciation and which she sustained without wavering beneath the cross, and lasts until the eternal fulfillment of all the elect. Taken up to heaven she did not lay aside this salvific duty, but by her constant intercession continued to bring us the gifts of eternal salvation. By her maternal charity, she cares for the brethren of her Son, who still journey on earth surrounded by dangers and cultics, until they are led into the happiness of their true home. Therefore the Blessed Virgin is invoked by the Church under the titles of Advocate, Auxiliatrix, Adjutrix, and Mediatrix. This, however, is to be so understood that it neither takes away from nor adds anything to the dignity and efficaciousness of Christ the one Mediator. For no creature could ever be counted as equal with the Incarnate Word and Redeemer. Just as the priesthood of Christ is shared in various ways both by the ministers and by the faithful, and as the one goodness of God is really communicated in different ways to His creatures, so also the unique mediation of the Redeemer does not exclude but rather gives rise to a manifold cooperation which is but a sharing in this one source. The Church does not hesitate to profess this subordinate role of Mary. It knows it through unfailing experience of it and commends it to the hearts of the faithful, so that encouraged by this maternal help they may the more intimately adhere to the Mediator and Redeemer.
Source: Lumen Gentium (Vatican.va)