If you utilise her Reflection Art and Water Absorbtion Art well you'll find the battle a pushover.
Any time it seems you're going to be attacked, use Reflection, then spam Lightning, Fire, Water and Summon Copy for a constant barrage and you're laughing. With the odd Mind Blast thrown in there you'll be fine for sure.
I did this with Reyn and Sharla as my team and couldn't believe the difference it made in the battle.