Just as a bit of background to this - DH has a younger sister and growing up she was always the family golden child and DH was the family scapegoat. When we all had kids SiL’s were the favourite grandchildren. There’s also a much older brother and sister. None of them are particularly close - we get together at Christmas and significant birthdays, DH chats on the phone sometimes, etc. We moved couple of hundred miles away 15 years ago so are somewhat out of the loop on family dramas. Our kids are all young adults now.
Randomly, a few years ago MiL visited us and apologised for the way she had treated DH growing up and apologised for the way she’d treated our children compared to SiL’s children over the years. We thought she’d had a massive health scare or something as it was totally out of the blue and totally out of character, but they’ve got along much better since, DH has a much better relationship with his mum and my girls have a much better relationship with their grandmother. Still not particularly close but a lot better than it was.
However, we’ve recently discovered MiL has been giving SiL a massively hard time about her kids and comparing them unfavourably to our girls which has obviously upset SiL. They’ve fallen out and we’ve now been dragged into the argument.
DH chats to MiL about our girls, she asks what they’ve been up to and stuff like that, but had no idea that she was then going back to SiL and using it as a stick to beat her with.
DH has tried to sort it out with her but she’s not having it and has decided it’s all our fault. DH hates conflict and hates she’s been made to feel that way so wants to address it with his sister.
I’m leaving him to sort this out how he sees fit, but he is upset by the whole thing and doesn’t want to leave it all to fester
Sorry, posted before I finished typing by mistake.
I guess I don’t really know what to do. I feel for DH who is keen to resolve the situation and for everyone to get along, but also don’t feel like we’ve done anything to apologise for.