Well, there's clearly not a lot that you can do to help them advocate within the system for their child. In the end you weren't successful, and that implies that others won't be either.

It might be more productive for you to help them focus on what other options might be out there. For example, their limited resources could make them eligible for a scholarship at a private or religious school that would be a better fit. Or maybe they have some flexibility in terms of neighborhood (maybe they are renting and could move more easily). Are there also charter schools around? And could they be eligible for support and help (maybe legal) because of their newcomer status?

Yes, you went through the same situation with the school, but in other ways your situations are very different. I'm thinking that re-fighting a battle that you already, admittedly, lost is not going to be productive in the long run for them or for you.

Instead maybe there's a way you can help another family escape the system that's failing these children. That would be better for the family and better for your own emotional state.

I still get angry when I think about some of the BS we had to deal with, but the more we focus forward, the better we all feel.