I've namechanged as this could be outing.
My DD is 9. Her dad has a 12yearold son. Yesterday she went to her dads and when I picked her up she was quiet. This morning she told me that her dad had to go out quickly but his son said he'd look after her but when their dad left he was saying how she needed to be punished (she wrote something in his diary last week but I told her off and she apologised). So he grabbed her wrist and when she started crying he said their dad doesn't like crybabies. And he threatened her if she told anyone.
Can I have advice?