While other martyrs suffered by sacrificing their own
lives, the Blessed Virgin suffered by sacrificing her Son's life—a life that
she loved far more than her own. So she not only suffered in her soul all that
her Son endured in his body. In addition, the sight of her Son's torments
brought more grief to her heart than if she had endured them all in her own
person. No one can doubt that Mary suffered in her heart all the outrages that
she saw inflicted on her beloved Jesus. Anyone can understand that the
sufferings of children are also those of their mothers who witness them.
--St. Alphonsus Liguori, A Year with Mary