"So does this mean it would be sinful to have children with your marriage partner?"
The simplest response would have been "Yes, it would be sinful" or "No, it would not be sinful"; hopefully with an explanatory clause regarding Joseph and Mary.
Of course not, within the bounds of a covenant marriage...
I didn't mean to confuse you, but if Mary is now considered "preserved exempt from all stain of original sin." ... the fall of man...that would mean she is no longer has knowledge of good and evil in a pre-fall of man condition...
Gen 3:16 was a condition placed by God on all women after the fall of man...