4br Rental with large family tenants

[Johnson Liv]

I have a 4bdrm SFR rental thats an hour from my residence so I gave my contact info to the local neighbors if anything arises. I just got a text from that neighbor noting that some additional people have moved in and there's now 9 cars going to the rental. I can go and visit, but I'm sure they'll have everyone out unless I show up unannounced.

The tenant is an older couple with 3 adult children for more than a few years now. I helped as a reference for the oldest when they moved into their own apartment. So I can only imagine they all moved back in, perhaps with significant others. 

Never had any inquiries from the neighbor prior. And this text comes in exactly 10 days after I raised the rent which hasn't been increased since the tenant moved in.

Your thoughts and opinions appreciated if this amount of tenants sounds right? Original was 5, but with 9 cars, I'm assuming it's now about doubled somehow.