Leave a card, leave and say a prayer for her safety.
Don’t leave, wait her out, at some point she may give up.
Supply her with booze until she passes out; then take her to the clinic.
Call the police complaining about the noise and the drunken woman that has threatened to do harm. When the police arrive explain the situation, that the woman may harm self or others and suggest the police give the woman the choice of being taking to the precinct and jailed for assessment or to the clinic you represent.