To help her perform better, you may have to change quite a few skills and decide on how you want her to function.
A) Debuff + tank set
Speed refined Dark Breath, because +3 speed is more handy than +2 attack Reposition Moonbow or Bonfire, because Draconic Aura scales off of Attack and she does not have a lot
A: Fury B: Windsweep (from Joshua) or Guard C: Basically anything depending on her teammates, except for Ploys, Smoke skills (Res Smoke works but only F Grima has it), and Threaten skills, and Res Waves S: Phantom Speed with Windsweep, or otherwise Close Defense
B) Enemy-phase set
Water breath with res refine Reposition or Swap Bonfire
A: Close Defense (from Joshua) B: Def Res Link (from 4* Sigrun) C: Attack Smoke (Kaze) S: Close Defense
She’d want a +1 merge and ultimately end up at 25 visible resistance. That moves up to 31 with the Res link buff, and then goes to 47 on enemy phase, with 56 defense.