There are several saints named Mary, though it is a safe bet that if you see or hear of “St. Mary” without any further qualifiers, the person you should think of is Mary, the ever-virgin mother of our Lord. She’s first before all other Marys, and all other saints for that matter.
If one refers to St Mary, with no further modifiers, one is probably referring to Mary, the Mother of God. Many, such as myself, use the title Blessed Virgin Mary to avoid this confusion.
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