My SIL was in tears when she phoned me. She informed me that the headlice were literally falling out of her hair and would assume that it has been that way for at least a couple of months.

She also told me that my D11 is starting to smell of BO and her clothes smell sweaty most of the time, it also doesn't look like she has been brushing her teeth and her hair is greasy and horrible.

I've been informed that there's no food in the house and just alcohol in the fridge.

I've told my SIL that if she's this concerned then she needs to tell my W as I'm in no position to do so.