In the US at least, if the photo is not used for commercial purposes (e.g. marketing products, causes) or used in a way that is defamatory (e.g. suggesting in some way that the subject is doing or represents something she doesn't), a waiver for journalistic work is not required. At least there is no cause of action in a court of law, other than being a nuisance suit.
Imagine if you shot a photo of a track race at a stadium, you would not be required to obtain a waiver from every one in the thousands of people in the stadium. On the other hand, if you suggested somehow that the race was a meeting of KKK members (which would be an inaccurate representation), that would be defamatory and subject the photographer to liability.