My son commented one night during a movie where a character was termed "Perfect" that God only made two perfect people: Jesus and Mary. He said that Mary never sinned. I am aware of Mary's conception without the stain of original sin, but does that mean that she never sinned in her time on earth?
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Immaculate Conception and Assumption
Mary: Ever Virgin (Fathers*)
Mary: Full of Grace (Fathers*)
Mary: Mother of God (Fathers*)