영국계 미국인 여배우.
셸리는 영국 런던에서 태어났다.

1965년 브로드웨이에 데뷔하게 되는데 <The Odd Couple>이란 작품으로 데뷔하게 된다. 1970년대에서 80년대까지 무대에 서면서 <Absurd Person Singular>로 토니어워드에 노미네이트 되었고, 1979년에는 <The Elephant Man>에 출연하여 여우주연상을 수상하였다. <Stepping Out>으로 1987년 토니어워드 여우주연상에 역시 노미네이트 되었다. 뮤지컬에는 <Show Boat>, <Cabaret>에 출연하였다.

셸리는 브로드웨이 프로덕션 뮤지컬 <Billy Elliot the Musical>에서 2008년 할머니 역으로 출연하였다. 2003년부터 시작된 브로드웨이 뮤지컬 <Wicked>에 마담 모리블로 출연하였고, 1968년부터 꾸준히 영화 및 TV에 출연하고 있다.

Film <The Queen of Greenwich Village, 2009> Actress
<Bewitched, 2005> Actress(Aunt Clara)
<Third Watch, 2002> Actress(Sister Rose)
<Law & Order: Special Victims Unit, 2000> Actress(Judge Pamela Mizener)
<Labor Pains, 2000> Actress
<Hercules: Zero to Hero, 1999> Voice(Lachesis)
<Frasier, 1998> Actress(Helen Moskowitz)
<Hercules, 1998> Actress(Lachos the Fate)
<Hercules, 1997> Voice(The Fates)
<Jungle 2 Jungle, 1997> Actress(Fiona)
<Hercules, 1997> Voice(Lachesis)
<The Road to Wellville, 1994> Actress(Mrs. Hookstratten)
<Quiz Show, 1994> Actress(Cornwall Aunt)
<Devlin, 1992> Actress(Charlotte Brennan)
<Little Noises, 1992> Actress(Aunt Shirley)
<One Life to Live, 1968, 1991-1992> Actress(Babs Bartlett)
<The Super, 1991> Actress(Irene Kritski)
<Coconut Downs, 1991> Actress(Sally Van Buren)
<Monsters, 1990> Actress(Lorna)
<The Cosby Show, 1988> Actress(Barbara)
<Spenser: For Hire, 1986> Actress(Irene)
<The Whoopee Boys, 1986> Actress(Henrietta Phelps)
<All My Children, 1981-1984> Actress(June Hagan)
<Another World, 1964, 1980> Actress(Iris Cory Carrington Delaney Bancroft Wheeler)
<Robin Hood, 1973> Voice(Lady Cluck)
<The AristoCats, 1970> Voice(Amelia)
<The Odd Couple, 1970-1971> Actress(Gwendolyn Pigeon)
<Some Kind of a Nut, 1969> Actress
<The Boston Strangler, 1968> Actress(Dana Banks)
<The Odd Couple, 1968> Actress(Gwendolyn Pigeon)
<Fire Crackers, 1965> Actress(Alice)
<Carry on Cabby, 1963> Actress(Dumb Driver)
<The Cool Mikado, 1963> Actress(Mrs. Smith)
<Dial RIX, 1962> Actress(Chambermaid)
<The Avengers, 1961> Actress(Ingrid Storm)
<No My Darling Daughter, 1961> Actress(First Typist)
<Carry on Regardless, 1961> Actress(Helen Delling)
<It's Great to Be Young!, 1956> Actress(Peggy)
<Rheingold Theatre, 1954> Actress(Bertha Schaeffer)
<Give Us This Day, 1949> Actress(Bit part)