Well, you know her name and address...
Go to every spam site on the net and fill out every form you can find. I mean everything. Russian wives, penis enlargement, credit card offers, free trials of newspapers, everything you can manage. Grab her phone number and do the same thing. Drop it all into every online virus form you can find.
The won't be able to get within 10 feet of her mailbox, and she will have to change her phone number.
That's the easy part...
Then, do what someone else suggested. Take out anonymous advertisements for yard sales, property and house sales, car sales, anything sales. You want strangers at her door.
To add to this disconcerting effect, advertise a free feeding of the homeless at her home every weekend. While you are at it, tell the local white supremacists that she is an activist for minority rights. Nothing like a burning cross in the morning to lighten the day.
Now someone stole my favorite little trick here, the observation van. You are responsible for keeping this from being traced. Get yourself a junker that looks road worthy, and park it near her home, with an old satellite dish on top aimed at her house.
Create some fliers that advertise votes to allow very strange things in the town you live in. Votes to allow things that she won't be able to tolerate or even believe, really. When she calls the offices to ask about them, nobody is going to tell here that it isn't true, as they have no idea what is going on half the time. Getting her to believe that the town council is about to vote to approve things like volunteer septic sharing, a reduction in water quality standards, the opening of a new 50 dollar a month government housing project a block away, legalizing bestiality, and things of that nature will work a long way to achieving your ends.
Pay some kids to ride skateboards around the neighborhood, and stick punk rock concert fliers under her wipers every day. Bands with names like: Ass Filth, Rancid Popsicle, Vomit Commando, you know, punk rock bands...
You find yourself some gangsters to roll about in your 'hood, beating their subwoofers on top of all that, and she will just about have had enough.
So, when you finally put the advertisements up for a BYOB ricer street racing super swimsuit party in her back yard, I don't think she will be around much longer.
You turn your neighborhood into her own personal hell, and she won't be a problem much longer.
Cheers,
Kennith