Duchess Ravenwaves came very close to cutting Lady's hair at times, especially in "Vanished," where she held Pixiesparkle hostage, then ordered that all the Pixietails leave them alone, including the one she was holding. She was only foiled when Pixiecurl, who was too far away to hear the order, snatched away her scissors.
In "Lake of Reflections," Hairball casts a spell that traps Lady's reflection under ice, weakening her power to summon the Pixietails. She ends up doing a lot of the work herself, especially in the final segment where she rides a makeshift sled and evades Hairball's magic.
In "Fire in the Sky" a giant fireball is menacing the kingdom, and Duchess Ravenwaves builds a dam to ration the water supply. The Pixietails help get the excess water to Shining Glory, who casts a spell that shoots the water at the fireball, cooling it off and saving the kingdom.