my [16m] sister [17f] is maybe going too far with her party lifestyle? should I tell our parents?

so my sister has partying pretty hard for a few months now, I think, I don't know how or when but I think she started hanging with maybe new friends or something and has been more active in parties lately
I have nothing against partying hard, but its definitely not my style so sometimes when she tells i can drop by the party if I want i dont feel like I really want to, but on saturday I asked her if maybe if I could bring some things to the party I could bring my girlfriend too, and she said it was OK after talking to the girl who had the reunion
so we got there, I had like, 4 beers which is way too much for me, my girlfriend had like two, we talked and danced a bit and she left early, after that my sister took me to a room with some of her friends and they were doing weed, drinking and had some pills they were passing around by kissing each other.
I think she was definitely drugged before she got there because she was not acting like herself, saying she loved me and maybe we should "share" a pill too. They all started saying i had to have one if I was going to stay so I just got up and left and they mocked me but whatever
I hadnt seen my sister like that ever, honestly it was kind of scary she was acting extremely hyper and laughing loudly in a strange way. this was the first I saw her "in action" but she's posting a lot in social media about being high, drunk, whatever. I jsut checked and there's been at least one of those posts a week on her Insta for the past 7 weeks, and otehrs before
So, I dont know if am medling with her life by saying this but, I dont think thats good for her, like, in any way, I mean im sure shes having fun but should she be doing these things? should I... tell our parents? would it help or would it only make things worst? If it made it worst, should i talk to her, what would i say and would it do anything good?
Am i being a busybody for even being concerned or am i like justified in my worrying?
tl;dr: Sister is going a little too crazy with partying drugs and booze I think. Is what she doing bad for her or is it Ok and Im just exaggerating? should i tell our parents or maybe talk to her myself?


Source.