We believe that Mary was bodily raised and then assumed into Heaven. Scripture tells us that it was done with Enoch and Elijah. A Catholic would say that Jesus would offer that same glorious assumption to His mother, who was chosen and blessed among all people of the world, to bring Him into the world.
Does anyone (Bible Christian) contemplate the magnificence of her calling? Does anyone here read what the OT says about how we are to treat mother/father/parent and think that Jesus would do less than that?
Her role in salvation history is greater than all forefathers, prophets and apostle combined, so whatever Scripture implies or tells us was granted to any other person, we believe was granted to the Blessed Virgin Mary many times over.
Eve was created without original sin, Mary was more privileged than Eve. Enoch and Elijah were assumed, Mary was more priviliged than they. The Ark of the Covenant was a pure vessel, Mary was purer than that was dictated to be.
Marian beliefs really follow very logically, in my not-so-humble-opinion, from her maternity.