I also would not let my son to be bullied in his own house. No amount of money is worth it. I always try make my best to find a solution instead of terming since it's super hard getting clients in this area, but in this case I would do it even if I have to loose the sister. I would first try to speak politely with the parents and see if I can keep the girl only, but if that would not be possible I would let both go.

If the dcb would be bullying another dck I do not think the victim's parents would be happy either. I would be leaving the daycare if I were in that position too.