We are national and the notary is done via web cam.  

This is a simple task that most all adults fully understand.

If you’re looking for an adult who may have lost their job during this time, I would pay them closer to $10/hr and $2/per sign to help them.

I have contacts within the Dept of Children and Families who can assist with partnering to help young adults who are aging out of foster care system and have not been adopted.

A good example I read recently was a couple's adult daughter moved back in after a divorce and their condo they occupied was no longer big enough. 

It's a civil matter, meaning adults need to figure out their personal drama and let cops focus on more important things.I would attempt to visit with all three occupants and explain to the daughter that she is not an authorized Tenant and that her parents want her out.

It was also imperative, and the right thing to do, to only ask prospective tenants "how many occupants (as opposed to how many adults and children)" will be in the home.  

Have any of you experience with adult employed roommates, not 18-21 year old students?

The adult children were going to have "some work" done on the house before listing it.

But the extra adult there is most definitely a violation of the lease, plus it's not safe for her.