In particular there was a couple and adult children from Minnesota that were looking to start investing. 

An additional solution might be to install a childproof lock on the back door (or whatever doors leads to the pool) so that only adults can open it. 

Only then can you serve the 14 day pay or quit notice and this needs to be attempted to be served in person by an adult third party (i.e. not you!) 

We run credit and background checks on every adult that lives in a property.

- Another question is "How many unrelated adults will be living in the property?"

Next tell them they have to work it out like two adults. 

There are 2 small children living on the 3rd floor and some very animated adults.   

had  a bunch of issues with the plumbing, so retrospective-- 1 adult isn't bad at all!

If college age and young adults are your target renters, this would be a great place to look.Most of the family neighborhoods are seeing house prices skyrocketing.

"Familial Status" IS a protected class, you cannot use that as a reason to not renew, unless you have in place, and have communicated to them prior to move in, an "occupancy" standard, such as "2 people (not adults, not children, PEOPLE) plus 1 per bedroom" or your local building department restrictions if any.Normally for a non-renewal, and depending on local law, you should provide NO reason.