Give them a little time. Bringing an older dog in can be more difficult. There is the possibility that they will just tolerate each other. That is how mine are and Angel was a pup when I added her.
I'm not a breeder and definitely not an expert, but from those I know females do get wierdly possessive when they are pregnant - its the hormones. Hope this isn't the case for you......
__________________  Sissy & Angel |