The Blessed Virgin Mary is the Mother of the great King by reason of a noble kind of conception, according to the message given her by the Angel.

[…] Because she conceived him on whose thigh was written, King of kings and Lord of lords, was Queen not only of earth but also of heaven as soon as she conceived the Son of God.

This is indicated in the Apocalypse where it says: A great sign appeared in haven: a woman clothed with the sun, and the moon was under her feet, and upon her head a crown of twelve stars.

Mary the Queen outshines all others in glory, as the Prophet clearly shows in the Psalm which particularly concerns Christ and the Virgin Mary.

It first says of Christ: Thy throne, O God, stands forever and ever, and shortly thereafter of the Virgin: The Queen takes her place at thy right hand, that is, in the position of highest blessedness, for it refers to glory of soul.

It continues: In garments of gold, by which is meant the clothing of glorious immortality which was proper to the Virgin in her Assumption.

For it could not be that the garment which clothed Christ, the garment completely sanctified on earth by the incarnate Word, should be the food of worms.

As it was fitting for Christ to grant the fullness of grace to his Mother at her Conception, so was it fitting that he grant her the fullness of glory at her Assumption.

And so we are to hold that the Virgin, glorious in soul and body, is enthroned next to her Son.

Mary the Queen is also the distributrix of grace. This is indicated in the book of Esther, where it is said: The little spring which grew into a river and was turned into a light and into the sun.

The Virgin Mary, under the type of Esther, is compared to the outpouring of a spring and of light, because of the diffusion of grace for two uses, that is, for action and for contemplation.

For the grace of God, which is a healing for the human race, descends to us through her as if through an aqueduct, since the dispensing of grace is attributed to the Virgin not as to its beginning, but because of her position through merit.

By position the Virgin Mary is a most excellent Queen towards her people: she obtains forgiveness, overcomes strife, distributes grace, and thereby she leads them to glory.

Bonaventure of Bagnorea (1221-1274): Homily, from Mattins of the Feast of the Blessed Virgin Mary, Queen, in the Old Breviary @ http://lzkiss.net/cgi-bin/horas/brevi.pl.