What she's doing is extremely dangerous to you. What if next time, her control isn't so great and she hits you when she intends to buzz you? I think you should definitely get the police involved - and not just the traffic cops. If she is really intentionally buzzing you with her car, I'm pretty sure that counts as assault. Yeah, its just your word against hers, but even if they say there's not enough info for a case, it would be good for a few reasons.

1) If she does end up hitting you or anything like that, they will have the prior complaint on file and be able to see it wasn't just a random accident.
2) If she's buzzed you more than once, its possible she's done other reckless road-rage fueled things. If there are other reports against her, yours would help get her off the street.
3) Even if she denies that she buzzed you, the police coming to her house asking for a statement should hopefully scare her out of doing it again.

Nip this in the bud. Don't wait for it to become a serious incident.