This was done after I sent 2 rent withholding notification letters and sought temporary housing elsewhere until the landlord repaired or remedied ongoing habitability, health and safety violations.

@Mario SanchezThat will likely do more harm than good.

Make sure their stay in EXCELLENT, or a bad review can do a lot of harm this early.2) Pictures.

I considered letting them do a shorter lease since I agree it wouldn’t be terrible to have it end in the spring, but I also don’t want them to get in the habit of negotiating and dictating the terms.

In short, relationships get harmed. 

I don't want any of my sibling's actions to jeopardize our verbal no-harm agreement while we get through this transition.I realize I'm asking for free help, but I'd be extremely grateful for any scenarios that can help me spot warning signs and correct if it's within my legal rights.

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

After a quick google search I find out she is in the habit of taking people to small claims court a few times per year for the past 5 years, meanwhile shes ruining hosts 5 star ratings by leaving false reviews. 

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

Both properties are habitable w/o risk to my tenants but these are things I need to take care of in the near or semi-near future.