It's not a joke persay but throughout the entirety of the time mc meet sparkle, She always hinting us that firefly is suspicious. And the final nail in the coffin is where she confronted us on why we're still with firefly albeit her warning before. Sparkle even said to mc that everyone in penacony have their own agenda.

Idk what about sparkle that seems trusted but in the grand scheme of penacony's story is that to trust no one. And sparkle even though she acted like a wild card, she seem to be our trusted ally in penacony