Stay with her through the night. Stop her from drinking any more alcohol. Try to get her to drink water or Gatorade. If she can eat, give her something bland like toast or plain rice. Look up "recovery position" - basically, let her rest on her side and stop her from rolling onto her back or stomach.
Nobody here can tell you whether or not to call 911 now. But if she loses consciousness or has a seizure, you need to get her medical attention immediately.
A gender neutral public toilet, even better.