Mary felt the consequences from the sin of Adam the same as everyone.
Christ never said that all who manage to not sin are saved, he said that all who are baptised and beleive are saved and those who do not beleive are damned.
My understanding is that Catholics believe that Mary "felt" the stain of original sin but never sinned. This directly contradicts Romans (and other places) where Paul specifically states all have sinned. Original sin isn't what keeps a person out of heaven. IF a person could live a pure life, they would go to heaven. The trouble is no one can by our very nature-including Mary.