On "What's Happening!!" Spencer turned herself into a household name at just 11 years old, playing the sassy and quick-witted Dee Thomas.

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, child star of "What's Happening!!" has died at 60 after a battle with cancer, though an official cause of death has not been announced.