Claudia was born around 1790 in a poor area of New Orleans. Her mother dies a victim to the Plague, and in September of 1795 she is found crying over her mother's decomposing body by Louis. Feeling desperate and reckless, Louis attacks Claudia and becomes intoxicated by the taste of human blood which he had been spurning and also by the pure strength of the girl's little heart. Although Louis flees the scene believing Claudia to be dead, the life in her is too strong and she survives this first attack; however, scheming Lestat brings Louis to the orphanage hospital where she lies and claims her as his daughter. Ignoring the stunned Louis, Lestat then infuses her with his blood, creating Claudia, the vampire child.
Louis, in love with his little beauty of a "daughter," proceeds to painstakingly teach Claudia proper manners and etiquette, as well as educating her mind in literature, philosophy and the arts. Lestat also loves her and the two of them go out to hunt together. Claudia appears to have been a natural killer, deftly using her helpless looks to lure her victims to her. She kills without mercy and with such flair, that even Lestat looks to her in wonder.
In several years, Claudia's mind develops way beyond her childish body, even though her two "fathers" still treat her like a doll-child. She begins to question her existence, why she does not change, who made her, and how did she come into being in that form. One evening, her frustration explodes. Confronted with her angry questions, Louis breaks down and tells her the truth, how both Lestat and he were guilty of her creation. Claudia, enflamed beyond anger, can only whisper "I hate you both!"
Deciding that she could not hate Louis despite what he had done to her, (was it because of her appreciation of his pain, or was it just out of convenience, I wonder...?) Claudia turns all her thoughts of revenge upon Lestat. In 1862, by fooling Lestat into believing that she wanted to make up with him, she poisons him (via a few pretty boys...) and then stabs him with a knife. Believing Lestat to be drained to death, she makes Louis help her dispose of the body in the Louisiana swamps. Shocked, dazed and appalled, Louis is about to leave Claudia, when for the first time in her vampire life, Claudia breaks down in tears. Louis, drawn back by the helpless despair in her sobs, returns.
The pair decide to cross the Atlantic in order to search for more of their kind and to learn more about vampire existence. The night before they set sail, however, a monster-like Lestat attacks the two. Desperate to save their lives, Louis throws a lamp at Lestat. The house (and most of New Orleans) goes down in flames and once again, Lestat is believed to be dead.
The quest for European vampires is more of less fruitless and Claudia tells Louis that it's time for them to hit Paris. Here, they encounter Armand and the vampires of the Theatre des vampires, but Claudia quickly senses that they are not welcome there. She also sees that Louis and Armand are drawn to each other. Understanding that Louis may leave her, she demands that he make Madeleine into a vampire in exchange for his freedom. Louis protests violently, but Claudia uses his own sense of guilt to attain what she demands. The deed is done and the two agree that they are now "even."
Only a few weeks after, the theater vampires strike and carry the threesome off. Lestat had come to Paris, unaware that his fledglings were in town, and told Armand how Claudia had attempted to kill him. This gives the vampires the perfect excuse to strike out at the foreigners who they mistrusted; this is even convenient for Armand and so he does nothing to stop his coven vampires. While Louis is locked up in an iron coffin for a whole day, Claudia and Madeleine are encarcerated in a cell with a sky-light. The sun rises; the rays burn Claudia, leaving nothing but ashes, and end a childhood that was too long.
Although Claudia dies here, her diary is later found by Jesse, working for the Talamasca. Jesse also sees Claudia's ghost. Perhaps the child demon's soul still haunts New Orleans...