Jesus saves, through Jesus God can help us.
Mary is not a deity, she can’t help anyone.
So is anyone who is not a "dead branch".
Those in heaven are also united to God (1 Cor.13:12; 1 Jn. 3:2) and are alive to Christ (Mk.12:24-27; 1 Cor. 15:22). God is God, not of the dead, but of the living (Matt. 22:32).
We are all in living contact in Christ.
2. Mary’s part in the sanctification of souls
22. The plan adopted by the three persons of the Blessed Trinity in the Incarnation, the first coming of Jesus Christ, is adhered to each day in an invisible manner throughout the Church and they will pursue it to the end of time until the last coming of Jesus Christ.
23. God the Father gathered all the waters together and called them the seas (maria). He gathered all his graces together and called them Mary (Maria). The great God has a treasury or storehouse full of riches in which he has enclosed all that is beautiful, resplendent, rare, and precious, even his own Son. This immense treasury is none other than Mary whom the saints call the “treasury of the Lord”. From her fullness all men are made rich.
24. God the Son imparted to his mother all that he gained by his life and death, namely, his infinite merits and his eminent virtues. He made her the treasurer of all his Father had given him as heritage. Through her he applies his merits to his members and through her he transmits his virtues and distributes his graces. She is his mystical channel, his aqueduct, through which he causes his mercies to flow gently and abundantly.