I've been ruminating on the title "Queen of Heaven." As the Mother of the King, it of course appropriate to bestow on her the title Queen. But this almost sounds honorary, whereas I suspect that the Church wants to convey something stronger. Let me offer this tentative proposal: We acclaim her as Queen because of her unique role as intercessor. Dr George S. Gabriel devotes a chapter of his book Mary: The Untrodden Portal of God
to our Lady's office as Mediatress. He distinguishes her role from the intercessory role of all the other saints:
The Theotokos' intercession and mediation, therefore, are not only incomparably greater but incomparably different in nature from those of the angels and saints. The intercessions of all other saints are only supplicatory in nature. Without Mary the mother of the Incarnate Logos, however, there can be no saints. She is one of the two persons in the mystery of the Incarnation. ... Her mediation and Christ's mediation operate as one in an unceasing, indivisible synergy in Heaven and in the world. Therefore she remits sins, intercedes, saves, heals, enlightens, sanctifies, guides, guards, protects; she routs demons and barbarian hordes, delivers us from dangers, turn tides, calms storms. A profound vesper hymn clearly distinguishes the unique nature of the intercessions of the Theotokos: "Unveil to us the boundless sea of your mercy and goodness and thereby wash away our sins, O All-Blameless One; for as the Mother of God you have authority over creation, and by your power you bring all things to pass according to your will. For the grace of the Holy Spirit abides in you, and unceasingly co-works with you in all things, O All-Blessed One" [Small Vespers, Saturday of the Fourth Tone, Apostichon of the Theotokos].
Among the saints and angelic hosts, the Theotokos alone, therefore, "has power to do all that she wills" [Theotokion of Tuesday of the Plagal First Tone]. To her is given "authority over creation," not merely honorary or titular authority but authority with power. For the vesper hymn tells us she "brings all things to pass" by grace, and not by grace that is occasional or tentative, but by full and "unceasing" grace that abides in her. By unceasing grace, her creaturely energy in Paradise becomes transfigured, and uncreated, as it were. For, like the mystery of the Incarnation, it is the mystery of two, one created and one Uncreated, co-working in a synergy that is as a single operation. For no creature is of its own nature "boundless." Only the uncreated, divine energy is boundless, unfailing, undiminished, inexhaustible, eternal constant. The efficacy of this synergy, therefore, spring from the one power and one rule (or "kingdom") of the Father, and of the Son, and of the Holy Spirit. (pp. 160-162)
For one who enjoys a union with her son that is closer than the union enjoyed with him by any other creature and who shares in his mediatorial work in such a unique way, it does indeed seem appropriate to entitle her "Queen of Heaven." Gabriel writes:
She was divinized by grace, and in the image of Christ's human energy, her human energy also become one (but unconfused) with His divine will. For, from childhood "she shunned human pursuits and surrendered to God the mind's reigning faculty and placed it in obedience to Him in all things" [Gregory Palamas]. In a relative sense, angels and saints also enjoy oneness with God, but regarding the Theotokos, it is incomparably and infinitely greater: "The difference between His friends and His mother, however, is infinite" [John of Damascus]. "She alone among all others was worthy and received all gifts of the Spirit collectively" [John of Damascus]. She is the "Queen Mother," the "Queen at the right hand of God" in Heaven, interceding "with motherly boldness." (p. 159)