I need your help /pol/

>Be me
>My sister is a (semi) single mother
>The father's aroundish, but he's a dirtbag
>She's white, the father's white, the baby's white
>She's having trouble controlling my nephew (3)
>I've been reluctant to step in, mostly because she's never asked me to, but also cause I'm not around much
>It's getting to the point where my nephew is bossing my sister around
>I have to step in

I've made it clear in the softest terms I could conjure in the moment that she is "half of the equation, trying to fill two roles," that the child needs cold (not necessarily physical) discipline, and that this behaviour has the potential to amplify if not put in check now.

She understands what I'm saying, or she doesn't. In any case, she is incapable of holding ground against a 3 year old.

I was hoping kind anons could post anything you might send to a single mother trying to raise her kid right.