Hello Jacy, welcome to the site. You too Kitty Ripper
Jacy, how long did you have Sophie? It can take quite awhile before cats will get along when a new one is introduced. Sometimes, it is rather easy, other times, it can take a few weeks or more. The best thing to do with a new cat in the house, especially if it isn't a little kitten, is to put the new cat in a room by itself. This way, both cats can get used to each others scents though the bottom of the door. You could put blankets and towels that Gary slept on in the other room with the new kitty. Cats are territorial animals and they need to work things out between themselves. If you are lucky, this can go rather easily, sometimes it just takes a while. I have 7 cats, 5 domestics and 2 wild Bobcats, that all live in the house together and love each other very much. Yes, there was and sometimes still are, a few cat spats here and there, but most of the time, they get along fine. Maybe you can try Sophie again? Just give her time and her own space for awhile, until she gets used to the new place. Cats can not be forced to get along with each other, they work it out on their own terms. Good luck with your new kitty family