She also had a mentally handicapped adult child and a son who never married. 

All adults know where they can push the limits. 

Totally agree on not babysitting adults.

I fully screen every adult applicant and have every applicant on the lease to make my ability to collect in the event of a default more secure.

I limit to two unrelated adults for even three or four bedroom houses.

I had my last rental for next school year get rented this week, and I took a group of young adults that weren't in school over students to hedge against the unknown, like you are referring to.

I had to do an eviction on a female my parents had helped out by allowing them to move into their unused 2nd story.

We each have to make that decision for ourselves as adults. 

I have been working in analytical fields for all of my adult live (pension actuarial student and IT/management consultant), and am looking at other ways of providing residual income for myself and my family.Thank you for taking the time to read my introduction.

As we get more questions about service dogs vs emotional support animals, it strikes me that if the adult who is viewing the house had a true service dog, that do should be with them when they were viewing the house, right?