I also would recommend calling the police dept. beforehand & see what they have to say about handling the situation. They will then be on the alert if you need to call them in an emergency. They would probably take her to a hospital (even without her consent) if she is a danger to herself or others. I had to call the police about my mother when I was a teenager. She had bipolar I & was very violent towards my brother & then at other times suicidal.
Please continue to try to get your husband to understand that this is a MAJOR deal & it must be addressed.
My heart goes out to you as you face this ordeal.--Suzy