As I recall from my Mariology class, there has been debate in the past about whether Mary was assumed at the moment of physical death, or immediately thereafter.
Much of the sections on Mary in the Catechism are drawn from Chapter 8 of
Lumen Gentium. That document states that Mary “on the completion of her earthy sojourn, was taken up body and soul into heavenly glory.” This is of course nearly identical to the words of Pope Pius XII in
Munificentissimus Deus. While the Magisterium in these documents was rather vague on the exact details of the glorification of her body, Father William Saunders, writing for EWTN states: "Since Mary was free of Original Sin and its effects (one of which is corruption of the body at death), since she shared intimately in the life of the Lord and in His passion, death and resurrection, and since she was present at Pentecost, this model disciple appropriately shared in the bodily resurrection and glorification of the Lord at the end of her life. (Note that the solemn definition does not specify whether Mary physically died before being assumed or just was assumed; it simply states, “Mary, having completed the course of her earthly life…”) Father Saunders continues by quoting a Bishop Theoteknos as stating “For even though her God-bearing body tasted death, it did not undergo corruption, but was preserved incorrupt and undefiled and taken up into heaven with its pure and spotless soul.” Then Father Saunders cites St. John Damascene: "St. John Damascene (d. 749) also recorded an interesting story concerning the Assumption: “St. Juvenal, Bishop of Jerusalem, at the Council of Chalcedon (451), made known to the Emperor Marcian and Pulcheria, who wished to possess the body of the Mother of God, that Mary died in the presence of all the Apostles, but that her tomb, when opened upon the request of St. Thomas, was found empty; wherefrom the Apostles concluded that the body was taken up to heaven.” (
ewtn.com/faith/teachings/maryc3c.htm
Sorry, I just took up a lot of space to say that basically, it’s hard to find a definitive answer. I think it’s reasonable to believe that her body was always glorified, since she was forever sinless. However, we can assume that she aged normally, so ?Perhaps she was restored to a more youthful appearance upon her Assumption? But that’s a whole 'nother area of speculation, isn’t it? When our bodies are restored, what age will they appear? Or will that even be relevant, for a glorified body, since “seeing” another in Heaven may have an altogether different meaning.