Having Dealt with Bertie growling at everybody, it could be normal for Raven. She is establishing territory. And she is mad at you. When I tried to introduce a kitten to RB Rosie, she growled horrifically at me. The kitten had to go live with my mom. And I couldn't get Bertie to stop unless I put her in time-out.

So good luck and keep trying. I have used Feliway and it helps somewhat.