The thing to keep in mind is prayers to Mary and the Saints is only possible because, living or dead, we are all members of the Body of Christ. Therefore, it is only through God’s willing it, that Mary and the Saints can communicate with each other in heaven or with us. So basically, Mary is able to hear as many prayers as God wills her to hear.
I great analogy that I heard once, which is so perfect because it relates the human body to the Body of Christ.
Keep in mind that Christ is the head of the Body and we are all members of his body.
If I took a large pin and jabbed you in the hand what would happen? You would most likely pull your hand away?
Well think about it did your hand pull itself away all on it’s own? Nope… the pain receptors send a signal up to your brain, which in turn sends a signal right back down to the muscles in your hand and tells your hand what to do?
It’s the same way with prayers to a member of the body. You pray to Padre Pio, the prayer goes through him and up to God. Since God is all loving and wants us to have a share in His love, He sends the prayer right back down to Padre Pio and gives him the grace He needs to hear your prayer.
Isn’t it amazing? God doesn’t need our help to do anything. Yet just like a loving Father He does the heavy lifting and allows us, his children, to participate in His work, giving us the opportunity to align our will with His.
Hope this helps,
God Bless