Mary, Queen of Apostles.

"The perfect model of this spiritual and apostolic life is the Most Blessed Virgin Mary, the Queen of Apostles, who, while she lived on earth the life common to all, filled with labours and care of her family, was always most closely joined with her Son, and cooperated in the work of the Saviour in an entirely singular way. Moreover now, assumed into heaven 'by her motherly love she takes care of the brothers of her Son who are still on the way [to their eternal home] and who are involved in dangers and difficulties, until they are led to the blessed Fatherland.' Let all most devoutly honour her, and commend their life and apostolate to her motherly care."

Apostolicam Actuositatem,Chapter 1.

In the Kalendar, before local feasts were suppressed, there was a feast of Our Lady, Queen of Apostles, that was celebrated on this date.( The Saturday within the octave of the Ascension.)

Though the office for that feast had been supressed, in a way, it has been brought back in the new breviary. It's collect was revived in 1968 as an optional collect in the Common of the Blessed Virgin during eastertide:

"Deus, qui Apóstolis tuis, cum María matre Iesu orántibus, Sanctum dedísti Spíritum, da nobis, ut, ipsa intercedénte, maiestáti tuæ fidéliter servíre et nóminis tui glóriam verbo et exémplo diffúndere valeámus. Per Dóminum."

In the 80's, the mass was also restored in the Collection of Masses of the Blessed Virgin Mary. (Which same, alsp has the mas of Our Lady of Mercy, patroness of our Order.)