The body of Mary was never discovered or kept as holy relic which would have been expected in the 1st century AD. Her ascension into heaven was recognized based on logical conclusions using this information as well as hints from scripture and historical documents from the 4th century onward.
The link below is to an article by Dr. Robert Stackpole concerning the evidence for the Assumption of Mary, celebrated every year on August 15 by Christians (i.e. Catholic).
https://www.thedivinemercy.org/news/The-Case-for-the-Assumption-of-Mary-3691
Other articles:
https://timstaples.com/2019/is-the-assumption-of-mary-historical/
(350 AD documentation by Saint Epiphanius concerning Mary ascension into heaven)
https://www.catholic.com/magazine/print-edition/how-to-argue-for-marys-assumption
http://www.unamsanctamcatholicam.com/apologetics/86-contra-protestantism/127-assumption-not-a-question-of-history.html
Dating the year of her bodily death (63 AD) and assumption to heaven:
https://churchpop.com/2017/09/10/do-we-know-the-year-of-marys-assumption-heres-the-intriguing-evidence/
Vatican 1950 Explanation of the Dogma (Set of Principles) to Use:
http://w2.vatican.va/content/pius-xii/en/apost_constitutions/documents/hf_p-xii_apc_19501101_munificentissimus-deus.html
