Denise Nickerson
Denise Nickerson (April 1, 1957-July 10, 2019) was an American former actress best known for her roles as the gum-chewing Violet Beauregarde in the 1971 movie Willy Wonka & the Chocolate Factory as well as Amy Jennings and Nora Collins in the soap opera Dark Shadows. Description above from the Wikipedia article Denise Nickerson, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Filmography
Dark Shadows
The Brady Bunch
Flipper
Search for Tomorrow
The Electric Company
Willy Wonka & the Chocolate Factory
After They Were Famous
Smile
Howard
Zero to Sixty
The Dark Side of Innocence
Pure Imagination: The Story of 'Willy Wonka & the Chocolate Factory'
Celluloid Bloodbath
Child of Glass
The Neon Ceiling
The Man Who Could Talk to Kids
Dark Shadows: The Haunting of Collinwood
The Koozebanian