The question is, can she defy a subpoena based on membership in the privileged Reporter class that an "ordinary" person could not defy?

It seems like the real question is how membership in the class is determined. If anyone who's acting like a reporter in a certain context (say, Adam Shostack interviewing me for his blog) qualifies, then I don't see the constitutional problem, though it may still be good or bad policy. If you've got to get a special card from the government that says you're a journalist, it seems like that's more of a problem. I guess other places where there's some right not to answer these questions exist, but they're mostly based on licensed professions. I gather your lawyer or priest has much more ability to refuse to talk than your doctor or accountant, and that your psychologist has a shockingly small ability to refuse to talk. Other than priest, though, all these fields are at least somewhat licensed by the state for other reasons, so that makes it easy to use possession of a license as a way to tell when someone really is a doctor, lawyer, psychologist, etc. For constitutional reasons, that's not really true for journalists.

GH

--John