Kitty is Johnny 13's girlfriend who unwittingly causes trouble for Danny.
When she got injured trying to get through the Ghost Portal, she empowered her jacket, ring and scarf so that whoever wears them will be possessed by her which were given to Jazz by Johnny until Danny stopped him, and later possessed Paulina to make Johnny jealous. She gets very jealous when Johnny's eyes roam to other girls. She can be selfish at times, but unless anyone is hurting Johnny (or if Johnny gets too lecherous of other girls), she is trouble free. She wears the common outfit of a biker chick (leather jacket, fishnet stockings, knee-high high heeled boots, etc.) In "The Ultimate Enemy", her future self appeared more elderly, but she still fights alongside Johnny.
When Kitty joins forces with Ember and Spectra in "Girls' Night Out", it is revealed that she can blow kisses that can make anyone that it hits disappear to parts unknown, if they stay that way for 12 hours, the ones who have vanished are gone forever.