All of these posts that respond with “nurses are nurses because __________ and she’s not that!” are unnecessary – the point is, she’s doing something illegal that can have grave consequences, and you know about it. That’s the long and the short of it, right? So, as some posts say, report it to the BON. I’m assuming that your state’s BON’s website is simple and easy to follow (mine is, thankfully). Consider what she could be doing behind closed doors – administering meds to a pt, changing drips, etc.
If you don’t have enough “evidence” (that is, if she hasn’t said in an official capacity, like on an application or telling a pt, that she’s a “nurse”), management should take care of it. Where I am, management has NO backbone whatsoever, so that wouldn’t help. So I personally would call my hospital’s “integrity hotline” – I’m sure that someone would listen to me, and do something.
But if she has said in an official capacity that she’s a nurse, she should be brought up on charges, and your in a position to facilitate that. You may be the one who protects patients from harm.