fighting cat - update

Hi All:
I wrote earlier in the week about my cats who have been companions all of their lives (6 years). Zart, the un-spayed female was viciously attacking George, our neutered male . He's twice her size - thank G*d he didn't fight back.
Anyway...after all the good advice I got, here's what's happened:
I've kept them separated.
I took them each to the vet. Each of them checked out OK.
Got a Feliway diffuser.
I had Zart spayed on Thursday, brought her home yesterday. All went OK.
I have kept them separate, but have done short periods of re-introduction, mostly because Zart gets upset about being locked in the bedroom and starts to claw the door (her paws bled a little) and George keeps waiting by the door looking for his friend. (And who is that crazy monster that LOOKS like her?)
Please let me know if this sounds right, as far as re-introduction, because the things I've read haven't been as specific as I'd like.
I usually bring Zart into a room where George is relaxing. I sit next to him with her in my lap and pet both of them, to have each relax together and to mingle scents. When one or the other gets agitated to any degree and won't respond to my voice (Shhh...and a gentle "no") I put Zart back in the room. I also bring her out to eat in the room where he is.
I know that it's only been a short while, but it seems that there's some improvement.
So...comments or additional tips?
How will I know when they're OK?
Thanks,
Craig

I guess if it's working for you, just do more of the same. You'll know it's OK when the two cats approach each other, do the nose-bump, the body-brush, and the butt-sniff without any dirty looks, hisses, head slaps, etc.

The only thing I would add is keep your alpha cat higher in position than the other one. If alpha is on the couch, but the other cat on the floor nearby.

Originally Posted by hissy

The only thing I would add is keep your alpha cat higher in position than the other one. If alpha is on the couch, but the other cat on the floor nearby.

Click to expand...

More goings on...
I inadvertantly left the door open in the bathroom adjoining the room where I was keeping Zart - I was in there with her, working.
I noticed that she wasn't in the room and went out to check, fearing the worst.
Imagine my surprise to find them each curled up on opposite ends of a windowsill! Peace didn't last a long time - George wanted to get down and that triggered some growling and hissing from Zart.
Question:
Am I right to separate her at that point and isolate her in her room?
How long do I wait between re-introduction sesssions?
We have a large - 3 foot cube - screen enclosure. Does it make any sense to place Zart in there in the living room? She gets SO upset about being confined in one room.
Also, please remind me about vanilla extract - what's the technique?
Thanks,
Craig