I don't know if it applies for brave, but at least they did the right thing. In the height of my youth and in the worst fight with my mother, I did go after her most precious belongings - I set her wardrobe on fire. I did put it out rather fast and the damage wasn't too bad, but I freaked her out and she called the cops. We got driven to the police station and a very empathic female officer sat down with us. In my country they have to press charges even if the victim doesn't want to in most cases. But instead of doing that she really talked it through with us. What was the problem, why did I go so far and so on. In the end she said "You know in some families small things happen and it breaks everything, while in other families big things happen but it doesn't change anything". And that was really the case. She solved our problem like a counselor even though that wasn't her job. I still have the highest respect for that.
That's encouraging, but it's also worth pointing out, she did the right thing by NOT being a "law enforcer"--in fact, by not even doing her "job"--but by being a decent human being instead. (And, like you said, that was good, but not brave.)
Maybe. But maybe she was a better law enforcer by seeing when to enforce and when to help. But lets not get philosophical ;)