Agnes is introduced in chapter 15 of the novel; when David, with his great-aunt Betsey Trotwood, goes to her father Mr. Wickfield's house in Canterbury, in search of a good school.

Agnes, whose mother is dead, takes care of her alcoholic yet affectionate father and of the house, as the "little housekeeper".

Her father's villainous clerk, Uriah Heep, taking advantage of Mr. Wickfield's alcoholism and his affection for his daughter, becomes powerful.

After Dora's death, Agnes consoles and encourages David to return to his normal life, and the profession of writing.

Cultural historian Peter Gay in an article titled "The Legless Angel of 'David Copperfield': There's More to Her Than Victorian Piety" stated that, she shows the effects of parentification.

The death of her mother and alcoholism and weak-mindedness of her father makes her more matured for her age, along with gifts of intelligence and presence of mind.

After Dickens' separation from his wife Catherine, Georgina stayed with him for the rest of his life and took complete responsibility for managing his household.