Biography
Marilyn Sue Schreffler (June 14, 1945 – January 7, 1988) was an American voice actress who provided voice-overs for several animated television series, mostly for Hanna-Barbera Productions.
Description above from the Wikipedia article Marilyn Schreffler, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Filmography
Cast Credits

Scooby-Doo's Spookiest Tales
Character: (voice)
MOVIE • 2003

Scooby-Doo's Original Mysteries
Character: (voice) (archive footage)
MOVIE • 2000

Scooby-Doo and the Ghoul School
Character: Winnie Werewolf (voice)
MOVIE • 1988

Yogi Bear and the Magical Flight of the Spruce Goose
Character: Bernice (voice)
MOVIE • 1987

Fatal Attraction
Character: Party Guest
MOVIE • 1987

Popeye and Son
Character: Olive Oyl / Lizzie / Puggy (voice)
TV • 1987

The Flintstone Kids
Character: Rocky Ratrock / Flo Rubble
TV • 1986

Heathcliff: The Movie
Character: Mr. Woodley's Secretary
MOVIE • 1986

Starchaser: The Legend of Orin
Character: (voice)
MOVIE • 1985

Pole Position
Character: Kuma (voice)
TV • 1984

Airwolf
Character: Angie
TV • 1984
Rose Petal Place
Character: Nastina
MOVIE • 1984

Newhart
Character:
TV • 1982

Simon & Simon
Character:
TV • 1981

The Pink Panther in 'Pink at First Sight'
Character: (voice)
MOVIE • 1981

Yogi's First Christmas
Character: Snively Throckmorton (voice)
MOVIE • 1980

Captain Caveman and the Teen Angels
Character: Brenda Chance (voice)
TV • 1980

Scooby Goes Hollywood
Character: Cherie / Sis / Receptionist (voice)
MOVIE • 1979

Casper's Halloween Special
Character: Winifred the Witch (voice)
MOVIE • 1979

Scooby-Doo and Scrappy-Doo
Character: Lorraine
TV • 1979