:)I apologize if this is not your intention, but based on your post, I think you have the wrong mentality.  

I'd love to get into a small multifamily, but when you're talking more than a duplex, there are few options and and a "good-ole-boy" mentality.

Currently she has two of her family members occupying the home, both with mental disabilities. 

I’ve had a jumble of these in my head and this gives great clarity. 

Hopefully this helps to add clarity on the overall process. 

What if someone has some other mental disturbance and doesn't pay rent-- but we're stuck with that too?

He came out fine but that year and half were rough mentally, physically and financially. 

All her stories are about addicts and mentally ill people that should not be allowed on the streets.

I now barely understand the nuance of life a little better, and realize I want to help people to live a better quality life by showing them how to approach the mental, emotional, and physical aspects of health in a more fulfilling way.  

My example above is not my exact situation, but it is my best attempt to strip things down to the bone to arrive at an answer for a core question that I've been mulling over for quite a while, but could not figure out myself.This discussion has helped provide much clarity for me, and I'm sure that it will help provide clarity for many others here as well.Thank you so much again!