Standing up to pee.

[Freedom]

I guess as long as you have an enclosed litter box for her use, all will be fine.

She may have a sore spine or a leg issue. I don't know how old she is, could just be arthritis. If it doesn't bother her, and if you are fine with the enclosed box, I guess I don't see a problem!

[AvaJoy]

If by standing up the pee is going up on the sides/back of box then she could be considered spraying or marking, an indication of stress. Of course you need to rule out any urinary tract infection. I have a female calico that does it on occassion, less now since one of the other cats has been removed who enjoyed tormenting her.

[Karen]

I actually asked the vets this on the radio show. They said it is just something some cats do, she may have gotten into the habit as a young kitten in challenging circumstances, and now she just thinks that's how it's done! Their advice was to enjoy it is just a unique part of her personality!