In the season 3 episode, "Mummy in the Maze", it is revealed that Brennan's favorite superhero is Wonder Woman, and that she always goes as Wonder Woman to the Jeffersonian's Halloween party. In "The Baby in the Bough", it is revealed that Brennan is a registered foster parent, at her brother's request, to take in his stepdaughters in case anything should happen to him and his girlfriend. In the season 3 episode, "Intern in the Incinerator", Booth reveals that Brennan's favorite flower is a Daffodil, her second favorite flower is a Daisy, and her favorite planet is Jupiter.