NEW YORK — Even more than most children, Sarah Polley grew up in a world of make-believe. Her parents were Toronto-based actors, and two of her four older siblings — she was something of a postscript, arriving in 1979, eight years after the next youngest — gravitated toward the profession as well.
Although she now questions whether her earliest auditions, at age 4, were fully self-motivated (“Who knows where that line was, between my interest and theirs?”), she took to the milieu as if born to it. Plucked from a world of backyard pretending, she booked her first film, “One Magic Christmas,” at age 6. Over the next decade, she would, in addition to film work, star in 67 episodes of the hugely popular Canadian TV series “Avonlea,” based on the works of Lucy Maud (“Anne of Green Gables”) Montgomery.