That's alright. I actually know the guy who wrote the GameFAQs FFIX monster list, he's pretty reliable and insanely knowledgeable of the game and game mechanics, but he has said the guide contains a few errors, maybe that's one of them.

I've figured out the attack powers and damage formulae for all of her other attacks...that's good enough I guess, I'm not wasting anymore time if it's so damn rare, assuming she even can use it.