The Gospel of the Transfiguration does not mention Mary’s specific role in salvation, but the Church tradition, especially Gregory Palamas in the East, speaks of the role of Mary in similar occurrences of contact with the divine glory, and in divinization.
Palamas affirms that our divinization is possible, and real, and that while we remain created beings, we are called to participate in the divine nature, in the divine life, through the divine Power. Mary was the first to achieve this, through grace.
Furthermore, considering the mystery of the Church as a communion of deification, Palamas explains that Mary imparts to us the contact with the divine life, and that this contact transfigures us. He actually says that it divinizes us, making us participants in the divine life.
Marian Encyclopedia