User blog comment:PhineasxIsabella/Phineas and Ferb Trivia/@comment-2217944-20100729222822

Yes and she is Appa on Avatar the Last Airbender. But you said "Thomas Sangster". Also, Kelly Hu is the actress who sings the song as the cousins of her character Stacy, who she also plays, so I suppose you are technically right. ANSWERS: 1. Doofenshmirtz and his Girlfriend 2. a. Dee Bradley Baker 3. Stacy;'s cousins (if you say Kelly Hu, you're still correct as she plays Stacy and her cousins)