Mother & Child Isle Fairy
Requirement: Balled of Gales
Simply warp to this island with the Ballad of Gales and you will receive the Fire and Ice Arrow upgrades (once you have the Hero Bow)

Big Octo Fairy
Requirement: Boomerang or Bombs
Look for the swarm of seagulls in the quadrant and shoot the Octo's eyes to free this fairy. She will double your magic meter.