"what is the difference between "assumed" (taken up) and ascention? (moving upward)"
Christ with his own power as God raised himself to heaven.
Mary was raised to heaven, not by her own power (she is of course not God), but by God's power.
The end result is the same, and the end result is the same for a person who dies and is later resurected and goes to heaven.
If Christ was not too good for death and rotting in the grave (for a short time at least) then it doesn't nothing to dishonour Mary or anyone else to die as well.
Thank you for the explanation.