Possible Clues:

• "Girls Lie Too" singer Clark
• Alabama congresswoman Sewell
• Sherri's twin sister on 'The Simpsons'
• Irwin of "Crikey! It's the Irwins"
• Clark with the #1 country hit 'Girls Lie Too'
• Animal Planet's "Crikey! It's the Irwins" co-star
• Australia Zoo owner Irwin
• "Glee" character Schuester
• Country music singer Gibbs