Consider buying the book the Bipolar Disorder Survival Guide, It is an easy read and it covers a lot of the apects of the illness from characteristics, meds, getting family and friends on borad with how to help the persons, and other great material. You can buy the book online from Amazon.com for under $20. Good luck
Keep the lines of communication open, get the book and don't panic at every mood change she has( pregnancy brings it's own mood change as I'm sure you remember). If she permits, go to the psy doc with her. If not, do the best you can and pray a lot.