Possible Clues:

• "Animal" pop singer
• Singer with the 2009 #1 hit 'Tik Tok'
• Billboard's Top New Artist of 2010
• Pop artist whose stage name uses a dollar sign
• 'Tik Tok' singer who spells her name with a dollar sign
• "Your Love Is My Drug" pop star
• "Praying" singer
• One-named 'We R Who We R' singer
• Pop singer who used to use a dollar sign for the third letter of her name
• Singer whose name was formerly stylized with a $