Hello Denise,
I don't have any actual issues with DD's MiL and FiL, apart from the fact that they have had a very strong influence with regards to the upbringing of DGD, who is now 13. DD went back to work only a few short months after the birth of DGD, their only child together, and although child-minders were carefully chosen, MiL played a large part in 'advising'. SiL is very close to his mother and bows to her knowledge at all times.
DGD's behaviour is very worrying. She's doing really well at school, but at home she screams at her mother and, although I really don't want to say this, seems to actively hate her, though adores her dad. The screaming and shouting that took place the other week resulted in the neighbours calling the police. DD wanted to speak to DGD's school about her behaviour at home, and is prepared for educational psychologists to perhaps become involved. However, SiL refuses for this to happen and says that they'll sort it out themselves without outside agencies becoming involved. He has told DGD that if her behaviour at home continues in this same vein, then she will be sent to live with her grandparents, and he means it. His parents have suggested that this happens, apparently. I've tried never to interfere, as it's their life, but if the other grandparents are preparing to take over parenting DGD, perhaps I should have tried to advise more. I'm really quite worried about DGD.