It's a really tough situation and I don't envy you having to deal with it

That's really sad about W and about her kids. I would worry that if you say something to her she might not come back. If she is struggling with depression, she may just find it all too hard. I think rather than saying something to her, maybe the other mums all need to pitch in and give her kids some attention and show them how to play with the other kids. I don't know that they need discipline as much as they just need someone to sit with them and show them how to play with other kids. If things are bad/sad at home too they might just be acting out. I don't think it is often that kids intend to do things that will upset other people, they often do them because there are other things going on. I think the kids need care just as much as the mum does.

I don't think you can turn a blind eye and you shouldn't have to because your kids have the right to feel safe and to have fun. But I think it might be an occassion to try and think outside the square a bit and see if there are some other things you can try to help out the kids and the mum.

I really don't know, but it does sound like a situation where a lot of caution is required. I do understand how incredibly frustrating it is for everyone else there though.