The Blessed Virgin generated us two times, in the incarnation and at the foot of the Cross: thus,
she is our mother twice over.
-St. John VianneyWe talked about this today during our discussion today on Blessed John Paul II for the Total Consecration to Mary using the popular 33 Days to Morning Glory book by Fr. Michael Gaitley (I'm doing mine later...they are doing theirs for the assumption).
For one, it helps to have someone who took Mariology with Dr. Miravalle at Franciscan facilitate your discussion. Why? Because, the reading specifically talked about Mary as Co-Redemptrix and Mediatrix of All Graces, and Dr. Miravalle actually (and rightfully!) petitioned the Holy See to declare these titles as dogmas of the Church. Yesterday's idea, tomorrow.
God did not 'have' to send His Son. The mechanism of our redemption could have come from anywhere, considering that God is omnipotent.
But let's take a look at the English translation of the Ave Maris Stella, verse 2.
Eve is the first sinner, taking from the fruit of the tree of the knowledge of good and evil. Adam assisted her, by staying silent, hiding, and then lying to God about their actions.Taking that sweet Ave, Which from Gabriel came, Peace confirm within us, Changing Eva's name.
Our Lady cooperated at the Incarnation by giving her Fiat. She said, "Behold, the handmaid of the Lord. Be it done unto me according to Thy word." Thus, God worked through a natural way, and Our Lord took on human flesh. This is not possible without the gift of Our Lady, Immaculate, and her Fiat. OK, so the conception by the Holy Spirit isn't natural. It's supernatural! But everything looks natural to the Jews, and is natural, in the sense that Jesus took on human flesh.
But wait! "Woman, behold your son. Son, behold your Mother."
In this scene at the foot of the Cross, Our Lord gives earthly protection to Our Lady to John, but more importantly for us he gives Our Lady to the Church. This might be the most important gift to us save for the sacraments. Not only does she work with her Son on the Cross by praying for the redemption of Man, but now, she gets to assist her Son in helping us out for all time. She is our mother. Mothers know best.
At the Wedding at Cana, Our Lady decided that the servants needed to listen to Jesus, even though Our Lord seemed rather reluctant (I find this to be a theme in John's Gospel; also, the name of Our Lady is not in this Gospel once. Alma redemptoris mater indeed.) to help, But nope. Jesus miraculously changes the water into wine, because a problem was brought to His attention by Our Lady.
This is all a rough sketch. Firstly, I am working off the memory of the discussion, secondly I don't have the theological expertise. I highly encourage additional reading on the Web. Dr. Miravalle has had a site dedicated to the fifth Marian dogma petition, and there are other authors with short posts explaining them.