Did she actually manage to leave something? I have several females who will vibrate their tail, just like a male does, but they don't actually do anything. It is a happy, excited response. I can get one of them to do it just by rubbing her back by her tail. She likes it so much that she vibrates but it is just a response like being tickled. She never wets anything.I just watched Misfit spray (as in marking territory) the side of my house.
Isn't that unusual behavior for 1) female cats in general, and 2) spayed female cats in particular???