I got myself a 2x Picnic Flora w/ +Def. The only skills I inherited to her was Death Blow 3, Glacies, and Reposition with Heavy Blade 3 as her Sacred Seal. I know it doesn't stack with Bold Fighter 3, but this was effective for when her HP threshold was below 50%.
She really doesn't need heavy investment since she's already a "beast" slayer.
Buffs:
L! Azura - Prayer Wheel w/ Atk Tactic and Def Tactic
YT! Olivia - Res Tactic
GW! Eirika - Joyous Lantern+ w/ Atk Opening 3