Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
It is not unusual for cats to develop subtle territory issues and devlop this aggression. It will intensify with a baby on the way because of jealousy and territory issues. Follow these instructions:
First, take Connie to your vet for an exam to be sure there is not a medical issue causing this.
Next, purchase a product called Feliway from your local pet store. It is a feline pheromone that acts as a calming agent. Follow the directions on the bottle.This will decrease Connie's anxiety especially towards teh new baby.
If these do nto help, your vet wil have anti anxiety medications such as Clomicalm to help her past this. Ask your vet about this. These are very effective when used along with the Feliway.
This LINK and this LINK has more tips.
Good luck and Congratulations!!
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta