I'm not impressed --- she took an already not-great situation, where she had co-workers who weren't really pulling their weight, and made it confrontational and poisonous. This is pretty obviously not a good way to treat your co-workers, and it doesn't help build the sort of positive relations that will allow you to help them improve, so you have people who still aren't pulling their weight, but now have reason to dislike you.

My advice? Don't do that, no matter what your boss thinks of it.

EDIT: I can't type.