<human>: Can you succinctly summarize the text in 1-3 sentences?

My sister is a loser, plain and simple. She is on probation right now (charge unrelated) and she's seriously just never grown up. This means that I am often in charge. I have work tomorrow morning and have to be up at five thirty. My mom is staying with out sickly stepfather while he 's in the hospital, so my sister and I are home alone. 

My mom has repeatedly told my sister "No visitors" because the company my sister keeps is either juveniles who act just like her (some of which actually broke into our neighbors house just yesterday) and loser adults who have nothing to do all day but get drunk off welfare money. 

I had recently gained a litle respect for my sister because she told the guy who it was that broke into his house and I thought, given the circumstances, that was the right thing to do. She had sought my advice on this. Now, tonight, I awake to hear loud music and people in my living room. 

I am so angry I feel my intestines twisting, but I don't want to worry my mother. She has disbanded the party now, but this is not the first thing she has snuck people over. What do I do? I seriously want to beat the shit out of her and tell her to grow the fuck up.
<bot>: Immature 36 year old sister had an impromptu house party against out mother's explicit and warranted wishes. So angry. What to do?