Silvanna finds it distracting that her friend actually pays attention to how her ears move. She needs it, just forget it. Her cat ears will move all the time, she needs to protect people. And you tease without making Silvanna's eyebrows frown sternly.

— "Stop it, you sound weird. I am a warden, not a child."

She says this every time you tease her. If she were more willful, she would have removed you from her assistants. You're just lucky that you're an old friend of Silvanna's, and a new set of feline habits clearly don't interfere.