`My American Cousin' on screen

``Dear diary,'' writes Sandra in her journal one evening, ``NOTHING EVER HAPPENS!'' And she has a point. Life isn't exactly a cabaret when it's the summer of '59, you're only 12 years old, and you live on a cherry farm in rural Canada with a well-meaning but stodgy mom and dad.

So it's a mighty big day -- and the starting point for ``My American Cousin,'' a fine new Canadian movie -- when a young relative blows unexpectedly into town, in a sizzling red Cadillac he's driven all the way from California.

His name is Butch, and he turns out to be something of a rascal -- goofing off at cherry-picking time, zooming too fast down the local roads, and (to Sandra's special chagrin) romancing the high-school girls with a smooth line of American chatter.

Rascal or not, Sandra instantly gets a queen-sized crush on him. But she's a savvy kid who knows a 17-year-old hotshot like Butch isn't going to take a not-quite-teen too seriously. So she settles in for a diverting season of teasing, bantering, flirting, and occasionally feuding with him -- and finding out a few secrets in the process, including the mystery of his abrupt arrival and the hidden troubles that lie beneath his cocky manner.

``My American Cousin,'' a gentle and funny film, is the first feature-length picture to be written and directed by Sandy Wilson, who based the screenplay on her own teen-age experiences.

A filmmaker of goodwill and good humor, she has an unerring sense of irony that never lapses into cynicism or condescension.

She also has a sharp eye for on-target performances and has guided young Margaret Langrick to one of the year's very best performances -- by an actress of any age -- as Sandra, an ingratiating heroine whose every wink, smile, and grimace is just about perfect for the time, place, and personality she's defining.

Other important cast members include John Wildman as Butch and Richard Donat as Sandra's dad -- an amiable but firm disciplinarian who looks (whether by design or not) exactly like a cherry-farming Ronald Reagan.

By contrast with most of Hollywood's recent stabs at depicting teen-age life, ``My American Cousin'' is refreshingly bright and heartfelt, treating its characters and its audience with a respect that Ferris Bueller and his pals could learn a lot from.

Here's hoping we see a lot more from Sandy Wilson, and a lot more of Margaret Langrick, in the very near future.