Families & Friends Of Addicts Support Group
Addiction affects more than just the individual. This community is dedicated to the families and friends of individuals suffering from any form of addiction. Mental health professionals are increasingly considering alcoholism and addiction as diseases that flourish in and are enabled by family systems. Family members react to the addicted person with particular behavioral...

Anyway, we can't do anything unless you see, or are told by the children that they are abused by dad, and then- you call the cops. Then your sister is mad, and they whole thing hits the fan.
Support your sister's recovery...know that the cycle may go on and on for years...and just try to be there for the kids as they need it.
We are powerless.