My own thought is, keep it very short and not rough or rude at all. My message was thus:
Dear Ms Marcus,Thank you for your thought-provoking article.
The insight I am moved to share with you is this: Abortion calls into question, not the unborn baby's humanity, but our own.
Sincerely,
[signed]
Nothing approaching ridicule or contempt. Just aiming to give her the cumulative impression that most people don't think she's OK
Absolutely fantastic. Bingo.