I'm not even sure what we should do about this, so any advice or similar stories would be greatly appreciated.

My boyfriend and I just moved into a duplex and we've been experiencing some pretty crazy-ass neighbors that are in the duplex unit connected to ours. Our roommate told us that about a week or so after he moved in, there were approximately 6 cops in front of the unit one night. He hung around outside to see what was going on and one of the cops said something about marijuana and then made our neighbor's son come outside, put shoes on, and go with them. About a week after we moved in with our roommate, our neighbor came over and told us that her ex-husband had slashed her tires the night before and wanted to know if we saw anything. The next thing we know, there's a poorly typed note on our door and the community mailboxes saying that on June 29, her son was kidnapped by her ex-husband and that he slashed her tires and that she is scared for her life. At this point, I started to get a little suspicious of her so I looked her up on the public court records and she has 19+ cases! Some are as minor as a speeding ticket, but there are things like drug paraphernalia, domestic battery/abuse, injury to a child, disturbing the peace and others. Coincidentally, the night she claims her son was "kidnapped" is the night she got the drug and injury to a child charges and the same night that the cops took her son from her.

After we got that last note, we were talking to our roommate and he said that the night before our landlord came over to measure our stairs because this same lady had claimed she fell down them and broke her wrist and was threatening to sue them for it. Now I guess while we were all out of town on vacation, something happened with her and the landlords because when we arrived home we noticed some signs posted on her car that is parked on the street. The signs said, "[Our Landlord] IS A LIAR! Discriminates against the disabled and is a SLUMLORD!!!" We kindly took the sign down and texted our landlord about it because we didn't appreciate it and we guarantee our landlord wouldn't. Today, another sign has been posted and they have been slamming their front door repeatedly. Not sure what the new one says, but I guarantee it's something along the same lines.

TLDR: Our duplex neighbor is posting rude signs about our landlord and we don't appreciate it. What the hell do we do about it?

PING ME!

There is nothing you can do about it, nor is it your responsibility. You don't want to get on this crazy lady's bad side. Whenever a sign goes up, text your landlord, as you've already done. If she gets too noisy or disruptive, call the police (check out the noise laws and such in your area for specific info).

You don't want to become friends with her, but neither do you want to become enemies. Be polite, but keep your distance. I also don't recommend taking down the signs - they are on her car (her property) and she could conceivably report it as a theft.

Keep notes of contacts you have with her - make sure to note dates and times. Take pictures (if you can do so discretely) of the signs and other stuff she may do. Hopefully you'll never need them, but you might and its best to have the info on hand if things escalate.

As stated above there's not much you can do other than tell your landlord and or call cops. To me it sounds like this lady has earned mother of the year award. I mean if the night her son was taken by cops for her neglect of a situation to be good for the kid is the same night she thinks he was "kidnapped" that should tell you either just hoe far out there she is from reality and keeping things straight or how high she has been getting. Either way no good will come from it.

Take pics of anything she puts up, if you even have to make it look like you're posing newly bought goods or clothes to get the proof so she wouldn't think you guys are being fishy then do it. Also ask your landlord what extra security you guys are allowed to do/have if you guys felt the need after any incident with her. Though at this point I'd be taking the extra line to be safe than wait for an incident to happen.

If she does anything to your guys' things call cops, even if only to lodge the complaint. Worst case you guys can always ask your landlord if they have any other comparable rentals you guys might get to like exchange into or something.

As of now though she seems like any other person who acts in a not so desirable manner and since it's not directly involving you guys, other than noise disturbances, there's squat to be done.