Does Mary possessed an "episcopal dignity" to lay hands and confer the gifts of the Holy Spirit?
The direct answer is Yes, in relation to conferring the gifts of the Holy Spirit to common priesthood and ministerial priesthood because Mary is the Mediatrix of all graces.
But, one may ask, Mary was not ordained and had not received the "holy chrism", the mark to "set aside or consecrate" a priest forever like Jesus the Eternal High Priest in the order of Mechizedek? Mary was already given a spiritual mark on Her soul, the angel sees the mark on Her soul saying "the Lord is with you".
Mary was "set aside and chosen and consecrated" not on earth but in eternity. While the Apostles must be ordained to effect the mark on their priesthood to become alter Christus, minister the sacraments to grant graces, and govern the Church to help in the salvation of souls.
All of this priestly marks and attributes was bestowed upon Mary by God in exalted fashion. Mary do not need the holy chrism to become alter Christus, She is the one who gave Jesus the Face of Christ in the flesh.
Mary was present in all the Seven Sacraments administer by a priest. While the priest can help the souls in aiding their salvation, Mary is the cause of salvation by Her Fiat.
Mary's priesthood is written in Her Seven Sorrows that pierced Her Immaculate Heart as a fulfillment of Simeon prophecy. Mary is the Co-Redemptrix.
" The Simeon blessed them and said to his mother Mary. Behold, this child is appointed to cause the rise and fall of many in Israel and to be a sign that will be spoken against. so that the thoughts of many hearts will be revealed, and a sword will pierce your soul as well."(Luke2:24-35)
Therefore, the priestly odination that set aside the priest is more profound in Mary as God is the one who had "chosen or set aside" Mary in eternity not just on earth.
Mary's ordination as royal & celestial Virgin Priest happened in the Mystery of Annunciation and Incarnation, She was not just filled with the Holy Spirit, She was "overshadowed".It was Mary's exalted Pentecost.
Mary's dignity surpasses the "episcopal dignity" received by the Apostles because She is the Queen of the Apostles. Mary's dignity surpasses even the dignity of all the episcopate who became Saints and Martyrs because Mary is the Queen of Martys and Saints. Perhaps the dignity of Mary is so great that Her dignity surpasses even all the angels combined including all the fallen angels. She is the Sovereign Queen of Angels and the Sovereign Queen Heaven and Earth. Mary bearing in her womb the King of Kings and the Lord of Lords has a share in the royal dignity of his beloved son Jesus Christ.
"The highest heavens cannot contained God whom She carried in Her womb."
The dignity of Mary was written and professed by the Catholic Church in the Dogmatic Constitution chapter 8 in Lumen Gentium.
Also, the episcopate or the Bishops in order to confer the gifts of the Holy Spirit must strictly follows the Rites of Confirmation instituted and instructed by the Church to confer the sacraments. The Bishop or the delegated priest must put on the holy chrism to the baptized person, say the invocation prayer and lay his hands to confer the gifts of the Holy Spirit. In contrast, the Blessed Virgin Mary as shown in the gospel of Luke when She visited her cousin Elizabeth, Her mere greetings was enough to confer the gifts of the Holy Spirit.
" And when Elizabeth heard the greeting of Mary, the babe leaped in her womb, and Elizabeth was filled with the Holy Spirit."(Luke1:41)
And not only Elizabeth was confirmed but also Mary fulfilled the prophecy on St.John the Baptisr.
" For he will be great before the Lord, and he shall drink no wine nor strong drink, and he will be "filled with the Holy Spirit", even from his mother's womb." (Luke1:15)
This passages in the gospel of Luke showed that Mary surpasses the "episcopal dignity" of all the Apostles as She can and had applied the merit of Christ won At the Foot of the Cross even the before Jesus had offered His passion, crucifixion and death on Calvary and even before the arrival of the Holy Spirit at the Upper Room during Pentecost.
Mary had conferred the graces merited by Jesus Christ in advance to St.Elizabeth and St.John the Baptist by Her mere presence and greetings.
The passage on Luke1:41 is a proof that the Theotoko's presence and by Her leading the invocation prayer in the Upper Room has the power to call down the gifts of the Holy Spirit to come down on all the Apostles for them to receive the gifts and be "filled by the Holy Spirit".
Does Mary need to "lay Her Maternal hands" to the Apostles or Her mere presence and prayer is enough?
The dignity of Mary cannot be compare to "episcopal dignity" bestowed on the Apostles but rather Her dignity must be revered and be bless by the Apostles and all men throught the generations to come.
" Because He hath regarded the humility of his handmaid, for behold from henceforth all generations shall call me blessed.Because He that is mighty, hath done great things to me, and holy is his name.(Luke1:48-49 Douay-Rheims)
In closing, Mary bears the mark of priesthood more profoundly than all the Apostles as She gave the Face of Christ in Her own flesh, and the one who set aside or consecrate Her is God the Father and in conferring the graces of the Holy Spirit, Mary is the beloved Spouse of the Holy Spirit and given Her role as Mediatrix can pour in the graces more powerfully.
Mary not only resemble an "episcopal dignity", She surpasses it! Both in the aspect of ordination as Co-Redemptrix and in conferring the gifts of the Holy Spirit as Mediatix.
Mary's priesthood is in the order of grace not in the order of Melchizedek.
Mary is the Advocate, Co-Redemptrix, and Mediatrix of all graces.
Mary Virgin Priest, pray for us.