If it is a temperament issue and not just a unique situation it would be best to get it under control NOW before you have a baby on your hands. Believe me, if your furbaby attacks your real baby -- it is not a great day. My daughter was bitten at 1 by my fiance's dog (in the face) she was standing around doing nothing and the dog got nervous. It was a trained dog who was 6 years old. She has a permanent scar above her lip that stretches as she gets older
Maybe try some training classes with just the two of you? Or the three of you with your fiance as more of a side helper?