Yes, I think it is risky to cite hostile work environment because state laws differ on interpretation and Federal Law focuses on protected classes. The OP has been threatened, however, which is why many people have suggested a police report. That goes to potentially criminal behavior, and the employer is obliged to provide a safe workplace.
I really think she needs to consult an attorney. If this goes on she may have a case of "constructive dischargement" per the EEOC.
This could get worse. If the OP or an RN reports the situation to the Medical Licensing board (as people here have rather blithely suggested) there could be major repercussions. The OP could be penalized for not being able to work nicely with others (Sue), or for being suspected of reporting the situation outside the office. She/they are technically protected under "whistle-blower" legislation for reporting to the Licensing board, but if you are the whistle-blower technical protection doesn't pay your bills when you are fired. We also all want her to leave with the best possible references, don't we?
Good luck, OP. Please talk to a lawyer before you quit This is important!
ETA. Also, although this may be redundant advice and I did not check the times the OP posted: if you are experiencing problems at work do not use your work computer to post about it! Everything on your work computer belongs to the company and can be used against you in a dispute!