- Mary Cattermole: "I don't understand."
- Harry Potter: "You're going to leave here with us. Go home, grab your children, and get out, get out of the country if you've got to. Disguise yourselves and run. You've seen how it is, you won't get anything like a fair hearing here."
- — Mary Cattermole after Harry Potter and Hermione Granger disrupt her trial.
Mary Elizabeth Cattermole was a Muggle-born witch. She lives at 27 Chislehurst Gardens, Great Tolling, Evesham with her husband and children. She is described as small with dark hair that she wore in a neat bun.
In 1997, Mary was accused of stealing the wand of a pure-blood or half-blood witch or wizard, and was brought before a trial by the Muggle-Born Registration Commission. She was interrogated by Dolores Umbridge and Yaxley, and would have been convicted and sent to Azkaban if not for the help of Harry and Hermione (disguised as Albert Runcorn and Mafalda Hopkirk respectively). Harry, Hermione and Ron (disguised as her husband Reginald Cattermole) assisted her and a group of Muggle-borns who had been in for questioning escape the Ministry. Harry advised Mary and Reg to take their children and flee the country while Voldemort was still in power.
Mary and Reginald managed to escape successfully, and later they returned home to get her daughter who was at Hogwarts and caring for young children.