If someone has PM'd you a nasty PM before, and you have responded only by stating clearly that they are not to PM you again, then she PM's you again, is this considered harassment (by anyone but me)?

Besides reporting it to a moderator, what else can (and should) be done? I don't want to have to turn off my PM's to prevent this person from sending PM's to me. I only opened her last message so I could send her a response that I was reporting it to a moderator.

It's not as if I want to "out" the person publicly, as I think her previous behavior has made it very clear that she has severe anger issues and a lack of social skills. If she weren't so nasty, I would feel very sorry for her. She's raged at people in threads before, then had her responses deleted. But I also feel that I shouldn't just have to be silent in the face of someone treating me like this.