Is it true there are so many relics of the Virgin Mary that put together there would be enough bones for more than one body?

No. The Catholic Church has solemnly defined that the Virgin Mary was assumed into heaven, body and soul, which means that there are no bones from her body available to be distributed as relics. The Church does believe in the value of relics though, and for reasons based on Sacred Scripture. There is a Catholic Answers tract that outlines the Church’s understanding of relics.