Felices sensus beatae Mariae Virginis, qui sine morte meruerunt martyrii palmam sub cruce Domini.
Happy the Heart of the blessed Virgin Mary, who without dying earned the palm of martyrdom beneath the cross of our Lord.
–from the Communion of today’s Mass
This is one of two feasts in honor of Mary’s martyrdom–she who suffered a real martyrdom under the cross, though she did not suffer the death of the martyr there. This feast focuses especially on the Compassion of Mary, whereas the other feast on September 15 is devoted to the Seven Sorrows generally.
Note the phrasing, on this feast of the Seven Sorrows– Happy the Heart of the Blessed Virgin Mary…. Suffering in, with, and through Our Lord always leads to joy.