Amitryptiline is used for bladder spasms in humans and animals. My sister was on it - a version called Baclofen - as her bladder got spastic very early in her journey with MS.

Yes, amitryptiline is also used as an anti-depressant, but does nothing for the peeing.

Ask your vet about Clomicalm. It is designed to CALM the critters. Plus, keep her in her "own" space; don't just set her out among all the others if you know that stresses her and makes her pee again.