you must report this and the kittens will be removed and looked after until they find new homes, the older cats can be neutered and the family can resume normal living, speak to someone at the RSPCA and tell them the whole story after all the 7yr old could have told her teacher or a class mate, but please just don't leave those poor kittens to suffer, if you cant bring yourself to make the call get a good friend to do it, if it is worrying you enough to post on here then you must do it and soon please.