The cause of things is not quite what we imagine in our empirical world. We think the powerful thing causes the less powerful thing.
So, when God answers prayer, we think he is the “full cause”.
But from God’s point of view, he is “sharing causation” with us. God “knows” he will do things for us, but our prayer is part of what he knows. He knows at least two causes for our answered prayer - when those two things happen, then the answer will be caused.
The cause we are already aware of is his power, or will, in action. The second cause is our prayer. By praying we are participating in the “work” (causation) of God.
And why does he want this? So that we are like him, doing the works of God with him. Doing this, working with him, we will know we are Children of His when we see him face to face, rather than being fearful that we are worthless in his presence.
Notice how we now honor Mary, as Queen of Heaven. We saw her without fear telling a problem to the King, and we saw the King being somewhat surprised at her timing, but we saw the King accept her timing and start his business as King early for her. turning water to wine. And now, not only the Jesus have a great reputation among us, but Mary also. And God wants this to continue in regard to her, wants her to look glorious in our understanding of her, and so he grants her the privilege of bringing requests to him as a part of his causation of answers to what we need and pray to Mary to help with. Always prayers build up the stature of the person praying to make them a co-causer with God, so that we all shine with our Father and our King in heaven.
Not sure I have said this clearly, hope so.