What do you suppose Mediatrix,helper etc.. means in co operation with Grace?
It means the way that Mary mediated for the stewards during the Wedding at Cana. She secured the miracle from Jesus for the manufacture of wine so that the stewards would not lose face by the interruption of festivities.
Like the stewards, Catholics go to Mary with their problems because Scripture (and experience) demonstrates that Jesus will grant miracles upon her request.
Without Mary’s yes(fiat) There is no Incarnation.
Her Co operation is there whether you like it or not
Pope JP II explains...
The Blessed Virgin’s role as co-operator has its source in her divine motherhood. By giving birth to the One who was destined to achieve man’s redemption, by nourishing him, presenting him in the temple and suffering with him as he died on the Cross, “in a wholly singular way she co-operated ... in the work of the Saviour” (Lumen gentium, n. 61). Although God’s call to co-operate in the work of salvation concerns every human being, the participation of the Saviour’s Mother in humanity’s Redemption is a unique and unrepeatable fact.
Despite the uniqueness of her condition, Mary is also the recipient of salvation. She is the first to be saved, redeemed by Christ “in the most sublime way” in her Immaculate Conception (cf. Bull Ineffabilis Deus, in Pius IX, Acta, 1, 605) and filled with the grace of the Holy Spirit.
3. This assertion now leads to the question: what is the meaning of Mary’s unique co-operation in the plan of salvation? It should be sought in God’s particular intention for the Mother of the Redeemer, whom on two solemn occasions, that is, at Cana and beneath the Cross, Jesus addresses as “Woman” (cf. Jn 2, 4; 19, 26). Mary is associated as a woman in the work of salvation. Having created man “male and female” (cf. Gn 1:27), the Lord also wants to place the New Eve beside the New Adam in the Redemption. Our first parents had chosen the way of sin as a couple; a new pair, the Son of God with his Mother’s co-operation, would re-establish the human race in its original dignity.
Mary, the New Eve, thus becomes a perfect icon of the Church. In the divine plan, at the foot of the Cross, she represents redeemed humanity which, in need of salvation, is enabled to make a contribution to the unfolding of the saving work.
Mary is our mother in the order of grace
4. The Council had this doctrine in mind and made it its own, stressing the Blessed Virgin’s contribution not only to the Redeemer’s birth, but also to the life of his Mystical Body down the ages until the “eschaton”: in the Church Mary “has co-operated” (cf. Lumen gentium, n. 63) and “co-operates” (cf. ibid., n. 53) in the work of salvation. In describing the mystery of the Annunciation, the Council states that the Virgin of Nazareth, “committing herself wholeheartedly and impeded by no sin to God’s saving will, devoted herself totally, as a handmaid of the Lord, to the person and work of her Son, under and with him, serving the mystery of Redemption by the grace of Almighty God” (ibid., n. 56).
The Second Vatican Council morever presents Mary not only as “Mother of the divine Redeemer”, but also “in a singular way [as] the generous associate”, who “co-operated by her obedience, faith, hope and burning charity in the work of the Saviour”. The Council also recalls that the sublime fruit of this cooperation is her universal motherhood: “For this reason she is a mother to us in the order of grace” (ibid., n. 61).
We can therefore turn to the Blessed Virgin, trustfully imploring her aid in the awareness of the singular role entrusted to her by God, the role of co-operator in the Redemption, which she exercised throughout her life and in a special way at the foot of the Cross.