Former child star Danielle Spencer, who brought sass as little sis Dee in the 1970s sitcom 'What's Happening!!,' died Monday after battling cancer. She was 60.

Dr. Spencer played the wisecracking Dee Thomas on the 1970s sitcom “What’s Happening!!” and became a veterinarian later in life.

Danielle Spencer, who played the precocious youngster Dee Thomas on the 1970s ABC sitcom What’s Happening!!, has died. She was 60. Spencer died Monday in a hospital in Richmond, Virginia, her What’s Happening!! co-star Haywood Nelson told The Hollywood Reporter .