Is There a Different Kind of Role by Which Mary Co-Redeems?

Is there a different kind of role that Mary has in her relationship to God and her relationship to Christ, which makes her injustice required to be given any kind of mediating or redeeming role? Or is even that role itself gratuitous in such a way that we can say that the mode by which Mary co-redeems is the same mode by which the saints co-redeem. I think that's coming back to the question as William posed it. It seems to me that then you have to admit yes, there's a different mode because that's just a different order of grace than what everybody else has.