:)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. 

This is by no means an exhaustive list - it's just a suggestion to get you thinking.

The real reason is they often exhaust themselves trying to work the graveyard shift (currently 12 hour time difference their from our EST) while still raising their kids, etc.

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

Does the shower have a fart fan and does it exhaust the air outside, not at all, or into the attic?

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.