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 .

Danielle Spencer, the actress best known for playing the quick-witted little sister Dee Thomas on the 1970s sitcom “What’s Happening!!” died on Monday at a hospital in Richmond, Va., her brother announced on Instagram. She had previously been diagnosed with breast cancer and undergone a double mastectomy and emergency surgeries. She was 60.

Danielle Spencer, who played the wisecracking and tattling little sister Dee Thomas on the 1970s sitcom “What’s Happening!!” has died.