Shelley with Farrah Fawcett, Jaclyn Smith, and Cheryl Ladd
in a 1979 publicity pic for Charlie's Angels
Shelley became Charlie's Angel Tiffany Welles in 1979. She was Angel no. 5, Tiffany "Tiff" Welles. She came to fill in the slot Kate Jackson vacated that year. Two years prior, Farrah Fawcett left the series and her slot was filled in by Cheryl Ladd. In 1980, Shelley left the series and her slot was taken over by Tanya Roberts. Jaclyn Smith was the only Angel who stayed with the series from start to finish.
a Spanish-language writeup about Charlie's Angels from 1981
Charlie's Angels was a phenomenon during its first run from 1976 to 1981. All the Angels became household names and each had their share of fans and detractors. Everyone who lived through that era knows who they are and which Angel they played. Kate Jackson was the smart no-nonsense Sabrina Duncan, Farrah Fawcett was the sporty California girl Jill Munroe, Jaclyn Smith was the sultry and mysterious Kelly Garrett, Cheryl Ladd was the cute and sexy girl-next-door Kris Munroe, Shelley Hack was the classy intellectual Tiffany Welles and Tanya Roberts was the street-smart tigress Julie Rogers.