Thank you both for your comments! I had been told that it may just be that they won't ever really get along, and I'm okay with that....things are tolerable at the moment, as I said. (It was awful at first....as they learned who was going to be "owner" of what room, etc....nastiness and chasing every day, even though we'd done several things to introduce them to each other gently.) And I finally decided, like I had to with my own children, that I'm not going to be put in the middle of it/take sides or interfere as they work it out. I think that was making things worse, or at least keeping them at a stand still.
Jpix, I do like the idea of the catnip and I think I will give that a try! They do both like it so maybe....gosh, if it even gets them a little closer for the moment. I really think if my kitty would relax and realize the other one ISN'T trying to kill her we'd be okay....but I can't seem to make her understand that.