Secondly, Mary is invoked in the Church under the title Mediatrix of all grace. All the graces which flow from the redemption of Jesus Christ are granted to the human family through the motherly intercession of Mary. Mary mediated Jesus Christ, the Author of all graces, to the world when she agreed to be the human mother of God made man (cf. Lk 1:38). And from the cross at Calvary (Jn 19:26) and as the final gift to humanity, Jesus gives Mary as a spiritual mother to us all: "Son, behold your mother" (cf. Jn 19:26). For this reason, Vatican II refers to Mary as a "mother to us in the order of grace " (Lumen Gentium, n. 62) and several twentieth century popes have officially taught the doctrine of Mary as Mediatrix of all graces, quoting the words of St Bernard: "It is the will of God that we obtain all favours through Mary." The Mediatrix performs this task in intimate union with the Holy Spirit, the Sanctifier, with whom she began the drama of our Lord's Redemption at the Annunciation (cf. Lk. 1:35).
Obviously they found nothing wrong with sainting Bernard, or the other saint including the one who said this:
So, then, it is taught in authorized books, that 'it is morally impossible for those to be saved who neglect the devotion to the Blessed Virgin;' that 'it is the will of God that all graces should pass through her hands;' that 'no creature obtained any grace from God, save according to the dispensation of His holy Mother;' that Jesus has, in fact, said, 'no one shall be partaker of My Blood, unless through the intercession of My Mother;' that 'we can only hope to obtain perseverance through her;' that 'God granted all the pardons in the Old Testament absolutely for the reverence and love of this Blessed Virgin;' that 'our salvation is in her hand;' that 'it is impossible for any to be saved, who turns away from her, or is disregarded by her; or to be lost, who turns to her, or is regarded by her;' that 'whom the justice of God saves not, the infinite mercy of Mary saves by her intercession;' that God is 'subject to the command of Mary;' that 'God has resigned into her hands (if one might say so) His omnipotence in the sphere of grace;' that 'it is safer to seek salvation through her than directly from Jesus.'"
And then you can find things like this:
http://www.marymediatrix.com/kb/kb7/9.shtml