I'd get another job!!! It is so sad for her, being bi-polar, but, I've had the experience of befriending a person suffering from raging bi-polar, and it is not healthy for you. I had to get far far away from that distructive behavior..
If it is a loved one, of course, that is different. Through love, patience and understanding, you find a way to deal with it. There is really nothing you can do to change it, but just be there and encourage them to stay on an effective Med.
Sending prayers for your Boss and for you..