Vaping is NOT safe and not allowed in dorms. (a good thing about covid is that most vaping supplies come from China and they are now scarce)
I’m make sure the smoke detector was reinstalled immediately. If roommate won’t do it, call maintenance. I’d then request an immediate change of room because of smoking. The smoking doesn’t have to be reported as happening in the room, just that the room smells like smoke from the clothing and ‘whatever.’ The school will figure out she’s smoking in the room.
Other kids in the room? Nope. Report it to the RA (who should be noticing this anyway)