Noma Dumezweni makes her Disney feature film debut as Penny Farthing in the film. As an English actress, she is known for portraying Hermione Granger in the original West End production of Harry Potter and the Cursed Child.
Penny is first seen when Jane Banks and her brother, Michael, enter the bank just as Wilkins remembers the jar of sweets on her desk which used to have toffee in it just as they follow him into his office. She later appears when Michael's children, John, Annabel, and Georgie, explore the bank while Mary Poppins waits to talk to Wilkins. Encountering Penny, they ask her for a sweet to which she agrees. She then talks to Wilkins who asks her to give him tea to which she agrees. Afterwards, it is unknown what happened to her after the Banks family got their home back, though it is possible that she remains the secretary.