Possible Clues:

• Astaire's sister
• "The Story of __ H": 1975 Truffaut film
• Singer with the albums "19," "21" and "25"
• 'Send My Love (To Your New Lover)' singer
• High-heeled Astaire
• '19,' '21' and '25' singer
• Mr. Rochester's ward
• One-named "Skyfall" singer
• "25" singer
• Fred Astaire's dancing sister