@Diane119, we just had the same situation last week. We too host remotely, but we have a security camera so we can see who arrives and if they're trying to sneak in more people or pets, smoke, etc.
Unfortunately, as luck would have it, we had a violent thunderstorm and the area lost power for about an hour, knocking our camera offline for several days until we could get there to reset it. The guests told me at the last moment that they were bringing in 2 extra guests, including one 9 year old kid which I reluctantly agreed to. However, my cleaners told me it seemed there were numerous kids and that they wouldn't have been surprised if there were more than 6 guests who actually stayed.
At the advice of @Jessica-and-Henry0 and a few others, I left a short, professional and factual review similar to what Jessica mentioned and gave them the thumbs down, for messiness alone, but didn't mention much about the extra people.
You might consider installing a camer which can run on wifi if you have Internet in your area.