I agree with Sanford 8916 about checking out a medical reason first. It could be food aggression or it could be that she was just having problems with so many other dogs being around (your mother's two I assume are not usually there).

I don't want to seem like a worriwart but I would have some concerns with you soon bringing a newborn infant into a home with a dog that is now giving you some concerns. I would surely watch her carefully and separate her from any dogs whenever you aren't present. I know that is almost silly advice as I am sure you will do that.

When one adopts a dog with an unknown past (as I did with Ripley) there are always concerns. Fortunately I have never (in three years) seen anything worrisome. That said, if I had real worries with how he related to Bella, I would have had to do what was in Bella's best interests. Thank God I didn't have to. I am sending you big (((hugs))) because I know you just want one big happy family and I am sure that the stress of being *slightly overdue* is not helping at all. (My own son was 16 days late! )