Is it possible to somehow preemptively/legally protect my wife and I against our adult daughter from future vindictive action e.g. false accusations, ERPO/"red flag" law (which we now have in place in Oregon)?

Here's the situation in a very small nut-shell:

• Adult daughter (30) is married and living in AZ
  
• She has a 10+ year history of serious mental illness e.g. bi-polar, BPD, suicidal, and has been locked in psych wards on numerous occasions since about 2008.
  
• Summer of 2018 she abruptly, and without clear explanation, cut off all contact with the family, including with her two younger adult sisters. Almost all communication about this was through her husband, who fully supports her and was emphatic that this is permanent.
  
• To say that I distrust them both would be a monumental understatement, and my wife and I have disinherited her from our wills, ensuring that our estate is split between our two other healthy daughters. As painful as this past year has been, she's made it clear that not only can they not be trusted with any of our estate, but they also want nothing to do with the family.

So my question at this point remains, beyond disinheriting her from my will, is there anything further I can do legally to protect my wife and I from something she may do in the future?

And yeah, this sucks.

Specifically exclude her from your will, don't just remove her. Name her and state your intentions that she receive nothing.

If she may be violent in the future, legally trespass her from your property.

Leave 1 cent that way they can't claim that you forgot.

Make sure you have all the medical records that you claim of.  It will still be a shit show if something goes south.  But easier to deal with if you have records.  Make a lawyer aware of this and have a file of documents ready.

I'm not up all the states that have recently adopted Unconstitutional red flag laws.
I'm assuming Oregon is one of the states that did.
I would seriously look around for a local attorney who specializes in this area of law and consult with them about this matter.
Based on what you posted, this is not a matter to cheap out on. I'm not saying you should spend the most money possible on an attorney, but I would hire the best attorney you can afford.
The most expensive thing in the world is cheap legal advice.
Good luck, and I'm sorry about your daughter.

Thanks everyone for the quick and thoughtful replies so far. To clarify, yes, my wife and I explicitly and specifically disinherited her from our respective wills.

Medical record-wise, she went seriously off the deep end and was first hospitalized right after she was married (20) and already an adult living in AZ. When things were relatively better, we'd attempted on multiple occasions to get her consent for medical records so that we could sincerely try and help, but she always refused. We do have the few records of when she was a minor and living with us, but she hadn't gone full psycho until after she'd turned 18 and moved out.

I just started doing a bit of looking for a local/OR attorney that might have some specific insight, but figured it wouldn't hurt to ask here in case there was something obvious and easy-to-answer that I might be missing.

Thanks in advance for any additional insights, and I will also update if I learn anything further that might help someone else in a similar situation.

Your biggest concern should be if you or your wife become incapitated. The mentally ill daughter could attempt to become your or your wife’s conservator/guardian.   You should write an express provision stating that  should you become incapacitated that under no circumstances should she serve in those capacities.

https://www.oregon.gov/DHS/SENIORS-DISABILITIES/SUA/Pages/Guardianship-Resources.aspx

I would add to this several affidavits from respected professionals indicating your competency at the time you execute that document.

Good stuff. Thank you!

I have seen this play out in real life.
You so want to avoid this for you and your remaining offspring.  It always seems the most mentally ill want to get ALL THE CONTROL of the healthcare.  Even when they have been absent for 20 years.

Is your will part of a comprehensive estate plan, including revocable trusts with clearly designated trustees, and medical and durable powers of attorney? This should be done with an attorney who specializes in such things, not cousin Bob, the general practice attorney in the family.

This.

Make sure your attorney is WELL versed in 'elder law.'

Tell them what you are trying to do.

If you have documents about her condition and previous treatment have them duplicated and give him a set.