u/Creative-Umpire-7910

Hi everyone I would like to start off by saying I am the oldest sibling in my family at age 19M and I have a younger brother age 17 and sister 16.I don’t know what to do or even say about what my younger sister does and I just need help because my mom and dad don’t do anything
My sister vapes, smokes, skips school, is extremely disrespectful (curses and says extremely mean things to both my parents), has sneaked out the house before, and now she is threatening that if my mom doesn’t put her in online school she is going to quit school in general. She doesn’t want to do this for any good reason and simply wants to be able to be home all day on her phone. Recently she even broke her phone and steals my laptop and forced my mom to let her use it. Everytime I get it back the screen is nasty (it’s touchscreen and is slower then before (it’s a cheap 250$ laptop I got for college). Anytime my parents even try to punish her she threatens to call the cops and acts like god because of it. She also sneaks to go to her friends house after school and ignores my parents calls and etc.
Whenever I tell her to stop in these crazy moments she says extremely harmful things as she knows I deal with depression and tried to OD before. I don’t know what to do and it just hurts seeing her run over everything and put more stress on my parents. My mom has cried to me and it hurts because I can’t do anything about it.
I am looking for any help available, I don’t know where else to ask but here. Thank you.