A few truths to ponder on this Feast of the Immaculate Conception.
1) She was free from all sin. So she did not pass on sin to Jesus’ humanity.
2) The only human person ever to be free from original sin was a woman, Mary. (Remember Jesus was a divine person who assumed a human nature. And he certainly was not 2 persons.)
3) Salvation came through a woman before it came through a man.