Are the children in danger? from fire hazard? If so I would feel obligated to help them. The adults have a choice in how they live, the children don't. They rely on other adults to intervene if the parents are putting them in danger.

I am terrified to intervene with this family member and don't know how to go about it and I can't find any help because right now I want to stay anonymous. If there are little children involved-will they definitely take them away from the parents? If so that would be even more tramatic for myself and for the parents. I do not not what to do and it is tearing me up inside.
signed, terrified & distraught