Both of us think it's because of the male cat. She hates him and they don't get along at all. He's really laid back and just wants to play, but whenever he's around she gets really tense. You can see it in her posture and everything. She was the first one, which is why I have a hard time giving her away if it's him that's making her so upset. But then at the same time, we don't know that that will truly solve the problem. What if we give my cat away only to have her still pee on the floor, and then we have to give her away, too?
Maybe we're terrible cat owners, but neither of us want to have to clean up cat pee for the rest of her life. She's less than five years old, and they live for up to 20 years. I don't think either of us have it in us to do this for that long of a time. Not to mention the cost of cleaning up after it all the time. We have two mortgages, we can't afford to be spending $30-$40 on a jug of Nature's Miracle every week or whatever.
I just don't know what to do. I've tried and tried and tried. I suppose we can try a different cat litter, though she never had any problems until her UTI and until he came along. She was fine after the UTI until we let them both in the house again.

I definitely think I'm done with pets after these two are gone. I just can't keep doing this for the rest of my life. I love animals, I really do, but I'm starting to wonder if I'm the right type of person to have them in my house. I can handle normal vet visits and normal maintenance and cleanup and expenses, but it's this other frustrating stuff I have a hard time with. It's like I can handle just about anything, but urinating on carpet is what will drive me over the edge every time. I gave my dog away because she was doing the same thing and ruined our carpet when we were trying to sell it, and now the cat's doing it. Animal urine is just my final straw, so to speak.