I hate having to deal with kids like that, they don't understand anything but intimidation. They're like dogs.
Regardless, tell her that you're going to sleep at a certain time and you're going to be locking the door because you must get sleep and can't deal with all her problems.
When she inevitably whines about this when she comes in at 2 am and wakes you up, tell her that she is the loudest and most obnoxious person and that she CAN'T just make noise whenever she wants. You have needs as well, and tell her that she doesn't want to mess with your sleep, and she needs to do this during the daytime or find another place.
Make sure that you match her everytime she tells you to just deal with it. Showing opposition will weaken her resolve. If necessary, keep reporting to the RA until they do something.
For now though just lock the door and have her initiate to you.
Millennials pretty much can't be reasoned with when it comes to their "fun." You're just going to have to Alpha Female her into the ground or get the RA to actually do something.