It means that mary had a unique role in God’s redemptive plan when she said yes to being the Mother of Jesus.
Since all graces com from Christ, and Mary’s womb carried Christ, then we could say that she cooperated in a special and unique way in God’s plan of salvation.
This mediation and cooperation is secondary to Christ’s work.
it is not put on par with Christ, it is not (name removed by moderator)lace of Christ.
It is a reminder to all of us, that we share in Christ’s role as Priest, Prophet and King to be lights of the world and to bring that light of Christ to everyone.
People sometimes get all hung up and think that the term mediatrix means that Mary is the sole mediator between God and man.
That is not what it means at all.
It simply means that she cooperates and works with God, as we are all called to do. Her role, was a very unique and special one, being that she is His Mother.