Louise Annabelle Crossby

 is a spoiled kid who moves to Danville in The Phineas Gardens. She dislikes Phineas and Ferb's big ideas similarly to Candace and has a bad relationship with Isabella.

Personality
Louise is very bratty. She appears to have millions of servants (or at least wants some). She originally tells Phineas to call her "Madame Louise Annabelle" but later doesn't really care when he calls her Louise.

Phineas
Louise originally absolutely hates Phineas but later kinda relaxes around him.

Isabella
Louise dislikes Isabella, to which Isabella shares the feeling.