Guilt. She should develop a conscience so it makes her miserable when she is immoral.
Let me point out that you are not so slick as to make that switch off the subject without notice. I just decided to go ahead and play the game. No one really cares for Mary who helps her hide from the truth and dull her own conscience. The minimum consequence for every wrongdoer should be that their own conscience convicts them to the point that they change their ways. That is the whole point of teaching morality in the first place.
And if she doesn't attain guilt but raises the child to be a fine upstanding individual, what then? Stoning?
After further thought to your comment, i have to agree with you. She should have experienced her guilt prior to giving birth so she could have legally aborted the child...........That would have made you happier, no?
Excellent post!