(Nick Ut | AP)Danielle Spencer, who played the wisecracking and tattling little sister Dee Thomas on the 1970s sitcom What’s Happening!! Spencer, who became a veterinarian later in life, died Monday at a hospital in Richmond, Va., after a years-long battle with cancer, family spokesperson Sandra Jones said. What’s Happening!! Dee, our brilliant, loving, positive, pragmatic warrior.”“We have lost a daughter, sister, family member, ‘What’s Happening’ cast member, veterinarian animal rights proponent and healer, and cancer heroine. “Danielle is loved.”Spencer also appeared on a mid-1980s reboot of the show, What’s Happening Now!