Mary isn't dead.
Anyone who has died on this world is dead to us and no longer lives in this physical plane.
Going outside of that to contact those who have died their physical deaths is condemned in Scripture and that command has never been rescinded.
There is NOTHING in NT Scripture that commands us to to pray to those who have died in this world. To do so is to participate in spiritism and seances.
The whole Mary worship doctrine is totally unsupported by any teaching in the Bible.