Well...
...if sexual intercourse is considered SIN; you might be right.
Within a covenant marriage of course not...
My point in using the Adam and Eve narrative is before they ate of the tree of knowledge of good and evil they were sinless and unafraid of God. After they understand the concept of shame...
Since Mary is now considered "preserved exempt from all stain of original sin." ... the fall of man
Mary now is free from "knowledge of good and evil" ?
To know what good and evil are, you have to understand what "sin" is...