User blog comment:Omega natsu2/Fairy Tail Episode 204: Stake My Life on Hospitality, Review./@comment-24102956-20141018040345/@comment-7418318-20141018075531

If her keys are none-combat or rather weak it'd explain why she wouldn't join the fight.

Her being a Celestial Spirit Mage would certainly explain how she was able to float the Zodiac keys up to their locks, instead of having to use a ladder (even though that scene was only added by the anime).