Some of those tests actually pose risk to the baby. And- like the Downs one, that has a LOT of false-positives associated with it. Most people (if the doctor doesn't recommend it) do not get the test, because it's not like it's going to change anything besides making you worry like crazy for the rest of the pregnancy!
Michele may be required to because of being high-risk, over 30, etc....but if she can opt out, I definately would!