You’ve had lots of good advice so I won’t repeat it, except to say that it doesn’t seem unfair that SiL has them every weekend and please unfollow him and his parents on Facebook, it’s not the same as unfriending and they won’t know about it, you just won’t see their posts.
My exSiL trotted back to his parents and then into the arms of another woman with whom he has two more children. He pays no maintenance for DGD. We’ve come to the conclusion, over the years, that he is a sociopath. BUT DD is unrecognisable to the person she was when married to him. She is stronger than I’d ever have believed possible. This is what I hope for your DD too. You’re doing everything right so just keep on! 
What fashion items remind you of your parents?



