Lady Lesso was the former Dean of the School for Evil. She was killed in The Last Ever After by her son Aric. She was a defining character in the series as Sophie's mentor. Her best friend is the Dean of the School for Good, Clarissa Dovey. In the final book it was revealed that her first name is Leonora.
Little is known of Lady Lesso's past. She became a teacher fifteen years before the events of The Last Ever After. She already had her son at the time, who was hidden in a cave near the School. Around that time she rose to the position of Dean. After five years, Evelyn Sader arrived and revealed Leonora's son to the School Master. Sader was evicted for committing crimes against students and Leonora was forbidden to see her son, an event that produced devastating consequences.
It is possible that she originally lived in Bloodbrook.
Lady Lesso is a very intricate character. Although she appears intimidating and isolated, she is kind and very courageous due to many actions she has done. To secretly visit her son for five years when that isn't allowed, breaking the terms of the Trial by tale in the second book, and more, Lady Lesso has proved she is a kind person, but can be a bit cold due to her tough past.
None of Leonora's family members were mentioned in the books except Aric. She had raised for a certain amount of time outside of the School and visited him regularly for roughly five years. However, the School Master suspended her privileges to leave School grounds, forcing her to abandon him. From that point on, Aric developed an obsessive hatred towards his mother.
He made a few appearances in A World Without Princes, and Lady Lesso mentions that Aric tried to kill her in the end-chaos of Trial by Tale. In The Last Ever After he was Dean of the School for New Evil, a position he shared with Leonora. Aric tried to kill her many times - poisoning her coffee, placing an asp in her toilet, etc.
During the final battle in Book Three, Aric took this chance to attack Lady Lesso, who was on Good's side. He delivers a fatal wound before being stabbed in the back with a broken stymph bone by Professor Dovey.
Clarissa Dovey is Dean for the School for Good, and is Lady Lesso's best friend. Lady Lesso explains to Sophie that Dean Dovey is, for her, what Agatha is to Sophie, her "true love". Sophie tries to dismiss this notion, but eventually comes to accept the idea that this is part of the balance which both sides need to maintain. Lady Lesso's last words were to Dovey. It is unconfirmed, but Lady Lesso was thought to be, by many fans, gay.
When Sophie arrives at the School for Evil, she does not want to accept Lady Lesso's assurances that she, Sophie, belongs with Evil. Nevertheless, Lady Lesso's beauty and sense of fashion helped Sophie begin to attempt to move beyond the restrictions of sack uniforms and awful food which the Nevers are given. After Lady Lesso's death, Sophie finds a large box in Lady Lesso's office with a gift for her. When she opens the box, she discovers that Lady Lesso wishes for Sophie to become the new Dean for Evil in her place. She considers Sophie to be like her own daughter.
- Many readers of the series suspected that Lady Lesso's son was Aric from some clues in Book Two, and it was confirmed in Book Three.
- Leonora means 'compassion and light', ironic for the Dean of Evil.
- Sophie and Lady Lesso have uncanny similarities. They both have 'good bone structure', 'a love for high heels', 'a vanity uncommon in Nevers' and 'are great witches when provoked'.
- Lady Lesso may represent an older version of Sophie.