<human>: It causes me a lot of anxiety to think that one day she could either get into a serious car accident and, even worse, die or kill someone else. Tonight she came home and said she only had 3 beers, but she was slurring her words. I want to report it so that she will stop, but if I do than she could lose custody of my brother [8 M] and his dad, my step dad, will get full custody of him. My step dad was physically abusive to me and my sister [17 F] growing up, and has abused my brother before the courts started watching him so meticulously when my mom filed for full custody. If he got full custody he would most likely be able to use and abuse my brother just like he did my sister and me. 

Is there anything else I can do to get my mom to stop drinking and driving? And while I'm here asking about my mom, is there a way I can learn to deal with the fact she is very negligent to my younger siblings and not put it on myself to step up as "mom" to them? It's more weight than I can handle but I also don't want to see my brother go through what I went through growing up and have nobody. I'm there for my sister but my brother has autism and I don't know how to deal with that on my own.

Can you condense the text into a few key points?
<bot>: How to get my mom to stop driving buzzed/drunk without reporting to authorities due to serious repercussions for my younger brother?