Vanessa Doofeshmirtz
Vanessa Doofenshmirtz is the daughter of the evil Dr. Doofenshmirtz, nemesis to Perry the Platypus, in Phineas and Ferb. She knows her father is evil, and just like Candace tries to bust Phineas and Ferb, she triest to bust her dad and get him into trouble with her mom. A recurring theme of the show is how Vanessa often meets with Candace, how she actually does not dislike Perry the Platypus, and how she never manages to show her mom that her dad is evil and builds machines in his home.
More soon! In the meantime please visit Wikipedia and the Vanessa's page on the Phineas and Ferb Wiki.