Absolutely none. She provides such a poor example of a magical girl that the students learn by doing the exact opposite of what she tells them.
Christine claims to have been a sidekick to Righteous Seraphim Luna Cycle back in the Eighties. My research tells me that she fought one rather low-key battle alongside her and has been living off the glory ever since.
Christine is the has-been's has-been. I mostly keep her around because it's funny, although I'm sure that if I fired her she'd come up with some kind of pathetic scheme for revenge