Bertha is a member of Chrestomanci's staff during Gabriel de Witt's time as Chrestomanci. She is mentioned by Erica.
| Chrestomanci's staff |
|---|
| Michael Saunders, Miss Rosalie, Erica, Mr. McLintock, Beryl, Frederick, Maud Bessemer, Joss Callow, Mary, Euphemia, Mr. Stubbs, Frazier, Sally, Will Suggins, Tom, Flavian Temple, Mr. Wilkinson, Dr. Simonson, Eddie, Laurie, Bertha |