There seems to be no depths to which human beings will not sink. The initial set of events - the death of the boy Peter - was horrific but the same man has now been found guilty of even worse behaviour.
The girl was not identified and there has been no disclosure of her parent's identity. I would conclude that she was a sister of the boy we now know as Peter. His mother, the partner of the killer and rapist, has been found guilty of a lesser charge connected with the sequence of the multiple rapes.
We will hear repeated calls for the crucifixion of the social care workers who are already in the Hall of Blame for Peter's death. That is understandable at first take but it does seem they were trying to brush out floor waters with a rake. The work load we have had disclosed must surely mitigate against even half-way protection. A phrase I have found telling was 'Social workers do not kill children'. For all we can know, the workers may well have had events on their work load where the risks were more apparent and gave priority to these. In the case of Peter and, in my conclusion, his violated sister, there would be no parental suspicion as to what was going on in a house of horrors but I see these events as another example of where we are in parenting. We have all forms of swift communication and surveillance but still failed these two kids. Punishment of the two involved here will do little to correct this - those involved right now in child abuse and neglect will just say 'they won't catch me' and continue their evil ways.
Just a small image of what I mean - how did the parents allow this to happen? Why did the photographer or bystanders not intervene? It may seem amusing but it illustrates just what I mean by negligent parenting.