Acolite,
on the "salvation of B.V.M."; Our Blessed Mother was preserved from the stain of Original Sin from the very first instant of her conception; by the foreseen merits of Our Lord's death on the Cross. Just as those born before the said redemption were able by these same foreseen merits, to have their sins forgiven and to save their souls. The issue of the Immaculate Conception was disputed in the Church for many centuries, because it was not clear how Our Lady could be redeemed by Our Lord, and at the same time conceived without sin. It wasn't until John Duns Scotus, a 14 C.Theologian was able to clearly reconcile both truths, that this doctrine was fully accepted and latter defined by Pope Pius IX.