She needs to get out of my dad's house, his health is failing him and she is abusing him.

Decide what a healthy rental rate for her would be and serve the Notice.I can't give legal advice, blah, blah, blah, you get the idea. 

You might see people saying any money not making 6% or more is a loser, but that idea makes no sense - for example, anyone who owns a lot of rentals (hell, any rental) without a healthy cash balance in their checking/savings account is crazy in my opinion, and yet that money earns more or less nothing.

This can only be done with a healthy local economy, and I think with some economic and business education, some of the 'graduates' of this process will go on to start businesses and provide real outlets for others.  

Fear is healthy.  

I have a tenant complained that her space - which is under a tall oak tree - is receiving a healthy amount of bird poop. 

When we moved into my place he started paying a portion that we both found acceptable - cuts me a check every month, +/- other things we need to balance out for other expenses or someone paying for someone else.It may not sound romantic, but I think it's an important part of a healthy relationship.  

When I get a little closer to retirement, or when NOI including mortgage payment is really healthy, then I'll get a PM :)  

Leaving the air circulating with fans or, better yet, leaving the Air Conditioning on will help to keep pets cool and healthy.

Even though we are healthy now, cannot assume same at mid-60s, we need to take retirement or partial retirement to focus on our health and life.If we sell current home, we can take 500k tax free capital gain and reduce rental mortgages (I can pay off one full mortgage and balance pay off 25% another rental).If I rent out my current home, it is 30 year fixed at 3.5%, tenants rent will pay all expenses and we will have the home free after 30 years (it will be gone to our heirs as we do not know whether we will live 30 years).What will you do if you were in our situation?