Attention Blockbuster clerks: Don't expect Julia Ormond to rent Sabrina anytime soon. Although the Legends of the Fall star will reprise Audrey Hepburn's role in the remake, Ormond's already overdosed on the film. ''I watched (it) four times before I auditioned,'' says the 29-year-old Brit. ''Then I got the role, and I've watched it three or four times. I'm going to have to stop.'' She's not bored just a tad depressed. ''That movie isn't good for my head,'' she says. ''(Hepburn's) waist gets smaller every time I watch the film. It gets smaller in between scenes! How did she do that?''