"Pray much and make sacrifices for sinners, for many souls go to hell because there is no one to make sacrifices for them."
When we do this, Mary uses what we give her to save souls--that is, to make them hers, to make them her children, uniting them to Christ and transforming souls into him, they live his life. Thus when we give Mary our prayers and sacrifices, we are giving her a tremendous gift that makes her happy beyond measure: She becomes a Mother again, souls that were lost become her children! That's amazing, that we can make this happen, that God wants us to do this, to cooperate with the Queen of Heaven in saving souls. Staggeringly amazing how happy we can make God and Our Lady and so many souls, eternally! And it just steals Mary's Heart away, a person wins her Heart giving her such gifts as priceless souls.