For her acting debut, Patterson starred as Rosaleen, a Little Red Riding Hood counterpart, in the Neil Jordan and Angela Carter film The Company of Wolves in 1984. In 1987 she starred alongside Diana Rigg in another fairy tale-inspired film, playing the titular heroine in Cannon Films' Snow White. Neither of these films were great commercial successes; however, the actress did develop somewhat of a cult following. She has only appeared in a couple of films since, both produced by Valiant Doll: her friend Lisa Gornick's independent film production company. The Valiant Doll film Do I Love You? marked her return to film after an absence of over a decade.
There is some doubt as to her birthdate: IMDB (the Internet Movie DataBase) states the year as 1972. But this would mean that Patterson was eleven, or else just turned twelve, when she made The Company of Wolves. The sleevenotes for The Company of Wolves Special Edition say she had just turned 13 when she auditioned for the film, which would give a more likely birth date of 1970.