@Sharon1157
It depends on a few things;
First off, do you charge a flat rate for the entire house, or on a per-person basis? Children under 12 I believe are suppose to be free (?) (I'm not sure if that's a hard and fast Airbnb rule or not -and I don't agree with it - infants ok, but children use beds and towels and everything else - like anybody else). But if so, were they all under 12? You might have a shot at something if they aren't.
Next, do you have enough beds? If not, some will have to sleep on the couch, which we prohibit, but house rules are largely unenforceable, and in that case, proving it would require "invasion of privacy" which is a delistable offence.
None of this is your fault, and it's not fair, but that's not how it works.
In the end, you have a choice of confronting the guest and risk a bad review, or just brushing it off.
You have to ask yourself if whatever incremental cost is worth encouraging a bad review (possibly a horrible review complete with fabricated atrocities you imaginarily committed, even a refund demand if the guest is particularly dubious).
No it's not fair, but the risks of confrontation are pretty steep. And the guest usually wins, even if they're the guilty party.
I'd be inclined to brush it off, and work to attract better guests in the future.
Good luck with it.