Why is my sibling so ignorant??

My sister is 18, recently graduated from high school, yet she still lacks the awareness of some things.

So basically, every night at exactly midnight, she always calls her friends. The thing is, it disrupts me from my sleep as the walls are very thin and she also yells.

I’ve yelled at her numerous times, even got on of my parents to do it as well, so she could shut the fuck up or take it somewhere else. Yet everyday, at exactly midnight, she does the same damn thing.

It’s getting very annoying, as I’m busy half of the day and coming home to sleep is the only time I rest. It’s also crazy that all she does is stay in her room the whole 24 hours, (only coming out to eat and go to the bathroom) having the time to call her friends whenever she wants, yet decides to pull this bullshit. She has all the time in the world, why is she calling them last minute?? And everyday as well??

I’m getting so sick of it. I’m pretty grateful that she’ll be gone for college so that she could take her shit somewhere else. I feel bad for her roomates.