K.,
We had the same issue with our cat. She is 10 years now, but we started having the problem with her about 3 years ago. The thing that worked for our cat is this litter called Cat Attract http://www.preciouscat.com/. She has been so good with that & it had been an ongoing problem... We had taken her to the vet & there was nothing physically wrong with her (although you might want to just check to make sure). Our cat was just acting out. It is a little bit more expensive, but it is guaranteed to work. Our cat has been successfully using her litter box now for 2 years...I probably could switch to another litter, but I don't want to mess with the success we have had. :) I found the litter at Petsmart, but you might be able to find it at another pet store. It is so worth it because I really know what you are going through. I have 2 girls that are 5 & 3, too! We are having our 3rd girl at the end of October...we don't have a fish, but we have a cat & dog. Email me if you have questions...
Blessings,
G.
www.shaklee.net/grapevineschmidts