I agree with two seperate food bowls and two seperate beds. They definitely do need time to adjust and realize that while they ARE sharing space, they do have their own things and Scruffy will realize that not EVERYTHING is being taken from her (ie. she's losing some attention from mommy and daddy, but she still has her dishes, her bed, her toys, etc.)
I think it's great that you rescued this new little baby. I'm sure you'll give him a WONDERFUL home. And Scruffy will adjust in no time.