If Kitty never takes her cat costume off, how does she go to the bathroom?
Probably an opening somewhere on the costume for her to.
Why didn't the police investigate all of the posters the cats put up with Kitty's picture on them?
If the cats speak English, why does Kitty only make animal noises?
Maybe she's a Wild Child? If not that, she probably does it out of choice.
Could be a classic comedic choice at play. We get direct translation of the cats as the viewers when in actuality they're meowing while Kitty is speaking human.
However, the other humans can freely speak with the cats. And Kitty still meowls at them.