@Kim597 Why would you leave no review? You could mention the guests' good points, i.e. following house rules, good communication, whatever is true, and then simply say it would have been appreciated if the guests had respected the linens by not spilling food on them, or something like that. (don't mention the blood, that just comes with hosting territory)
The fact they had kids is no excuse- it's up to the parents to make sure their kids don't eat spaghetti on the duvet.
Please do not leave star ratings that don't jive with the written review. Hosts who do not use Instant Book have no access to guest star ratings, so it's a disservice to us to not mention something in the written review that you've felt necessary to rate lower on with the stars.