@Paul8467
Out of interest, how old is the child? Do you think he/she is under two or over? The reason I ask is that Airbnb does not count 'infants', which it categorises as under two years old as paying guests. Even then, the guest should have disclosed it.
I'd be pretty mad by now about their behaviour and would definitely have brought it up. It sounds like you are expecting a bad one even if you don't challenge the guest on their behaviour/damages. However, I see that your listing only has nine reviews and I can understand why you'd want to avoid a negative one so early on.
If the stay is a long one, then I think you would have to mention something to the guests as they are clearly a security risk. However, if they'll be gone very soon, I would maybe just keep an eye on the situation and follow @Enri1804 's advice RE leaving an honest review/ratings and requesting payment for damages after they have left. As he mentions, timing is quite important for this. You want to leave the review and request for the damages as close as possible to the deadline so that the guest doesn't have much time to retaliate. However, if they go ahead and leave a review before, then it doesn't matter, you can just go ahead.