Thought I'd mention - there is a product by Kleenco called Kitty Scram which is the best pee-smell remover that I have ever used. It's usually sold at the commercial level, but we were able to get alhold of some. I've used it on hardwood floors, carpets, and fabric. They have a web site, www.kleenco.com, that might help you find a local distributor.

The stuff is wonderful, and smells like bubblegum (which is a lot better than the smell of kitty-pee! )

One final mention, I had commented earlier that there is a power struggle going on. Maybe you need to "crown" the queen, so everyone knows which of the two are "in charge", and it might help settle things down a bit.

Good luck!