Udonna is a powerful sorceress who trains the Power Rangers in the art of magic and is their guide to unlocking the secrets of the Xenotome. She is an inhabitant of the magical dimension and was around during the great battle years ago where she lost her husband and son. As an accomplished sorceress, Udonna is the White Ranger. Her mystic power gives her the control over snow and allows her to freeze evil in their tracks. Unfortunately, her Snow Staff fell into the hands of evil, which prevents her from accessing her morphing powers. With the arrival of old friends such as Daggeron and Jenji, she eventually confessed to the rangers about her past. Udonna was once married to Leanbow, Daggeron's mentor. Together they had a male infant named Bowen. During the great battle, Leanbow went to fight in the underworld and Udonna gave Daggeron to take Bowen to a safe place. Her powerful sister Niella, the gatekeeper sacrificed her life in lowering the gates of the Underworld as requested by Leanbow, who was on the other side fighting back the forces of evil. Udonna did not see Leanbow, her son Bowen, Daggeron or Jenji until years later. She raised her niece Clare on her own as her apprentice.
When the rangers were captured and taken to the Underworld, Udonna disobeyed Clare and used the Book of Dark Spells to send herself into the Underworld, even though she might loose her magical powers in doing so. The Master almost destroyed her as she saved the rangers and Koragg saved her in regaining his lost memories. Udonna was more than thrilled to have Lianbow back. But their reunion was cut short, when Udonna was great weakened and lost all her powers. She was taken back to Rootcore were Clare covered her with Nick's baby blanket. She recognized it as the blanket she wrapped Bowen in. Udonna revealed to Leanbow, Nick, and the other rangers that Nick was really her son. When Leanbow sacrificed himself again by sending the Master back into the depths, Udonna didn't loose hope that Leanbow was still out there. Udonna set out to find her husband and was eventually joined by Clare only to be captured by Hekatoid at the Lake of Lament where Leanbow eventually was at. The rangers attempted to save Udonna but ultimately was the unique trio of Clare, Phineas and Leelee that were able to retrieve Udonna. Leelee even had stolen her Snow Staff back for her.
Once Udonna had her Snow Staff back, she was able to transform into the White Ranger and defeat Hekatoid. Udonna found Leanbow in the Underworld by astral projection and used her Snow Staff to re-empower him, giving him the powers of the Wolf Warrior. Udonna fought bravely against Sculpin but was taken by him to the Underworld. Necorali saved her and a revived Itassis defeated Sculpin. Udonna returned to the surface world and along with her husband, son, Daggeron and the ohter rangers defeated the Master. After that, she went to visit Nick's adoptive parents with Nick and Leanbow on motorcycles.