Now that you have read about the Holy Innocents, Martyrs, you can better understand one of Mary's titles, the honorific: Mary, Queen of Martyrs.
As Virgin and Mother of Jesus Mary gave birth, and within days King Herod created the first martyrs, slaying dozens if not more of local babies who fit the timing of possibly being Jesus. With the martyrdom of the Holy Innocents, Mary, who would face the worst as Jesus himself is martyred as an adult, Mary in a very real sense took on her first title as Mother of all Martyrs, for the Holy Innocents were born into martyrdom as Jesus was born as the bodily reality from Mary.
Goya has a painting of Mary as Queen of Martyrs, and you see that they are in heaven with her, of all ages. Mary becomes the adopted mother of all who are martyred for her Son's sake.