Hanna Rosin responds to Palin declaring that she thought for a moment about aborting Trig:
...anyone who's ever been to a certain kind of church knows that this is a lead-in to a personal narrative, known as a testimony. The testimony follows an established formula, similar to a VH1 Behind the Music special: First things are going well, and then a moment comes when the subject flirts with sin, and their faith is tested. In the end the person triumphs and their faith is redeemed.
So in some sense it's "true" that Sarah Palin thought about it, but also true that there was no other possible outcome than she was going to ultimately decide to "walk the walk" and not just "talk the talk," or she wouldn't be telling the story.