I saw what type of people they really are when they brought several adults and children over yesterday. 

Or kicked in just as fast by an adult. 

But then things took a turn for the worse in October when her adult daughter (also a tenant in that home) was supposedly hospitalized for COVID and was out of work for a couple months. 

It sucks, but that is how being an adult works.

I think you can limit the number of adults in one property as part of your criteria (verify for your state).It's a red flag for me to need that many people to make your minimum income/rent requirement.Make sure you are familiar with the fair housing rules and you apply your criteria the same way for any applicants to your properties.

They must make 3x the rent, they must pay an application fee, every adult must apply and be screened, etc.

Kids will be kids and they will run/jump and be more noisier then an adult, so just avoid the possible problem.I have an up/down Duplex property and this year both tenants have started to not get along with each other due to non-noise issues.

I have a 2 adult/2 kid (6/9) family living at my 3bed/2bath rental for about 18months.

Turns out neighbor was right and they lied back then because on a recent visit where I had to fix a problem the adult daughter verified that she was living there from the start.

I hate the adult diaper answer, but IT DEPENDS.