Born in 1949 in Bristol, England, she began her career as a child actress, achieving early success with roles in "The Children's Hour" (1961) and "The Birds" (1963). She transitioned seamlessly into adult roles, gaining recognition for her performances in "Invasion of the Body Snatchers" (1978) and "Alien" (1979). Known for her versatility and expressive acting, she has worked extensively in film and television, earning numerous accolades, including Emmy nominations for her work on "The X-Files" and "ER."