Several years ago, Mary Steenburgen and Malcolm McDowell met on the set of "Time After Time," the H.G. Wells/Jack the Ripper thriller in which they costarred. Soon afterward they were married and Steenburgen's career took off, earning her an Oscar for her performance in "Melvin and Howard"; McDowell, meanwhile, became less visible and appeared in the likes of Penthouse magazine's widely attacked "Caligula." But now Steenburgen and McDowell are teaming up again, and you couldn't ask for a more wholesome project: "Cross Creek," with Steenburgen playing Marjorie Kinnan Rawlings, author of "The Yearling," and McDowell portraying her editor Maxwell Perkins. The film will be directed by "Norma Rae" director Martin Ritt, who's reteaming with producer Bob Radnitz and cinematographer Johnny Alonzo, both of whom worked on Ritt's "Sounder" several years back.

Jack Lemmon is not bothered by the State Department's recent three-page rebuttal to the Costa-Gavras film "Missing," in which he stars; after all, he's still on speaking terms with the current administration, dining with the Reagans at the White House recently. The State Department only bothered to reply to the film because it's so "strong and powerful," Lemmon has said, and he cites a strange example to prove just how strong it is: Audiences, he says, are so taken by the film "they start fist fights." What theaters has Lemmon been in lately? And director Lina Wertmuller will be looking for a good editor on her next project, a mother-and-daughter story titled "Tieta," starring Sophia Loren. The film will come in two forms: a two-hour theatrical release and an eight-hour television version.

It's okay to keep kids out of R-rated movies, said the Michigan Court of Appeals lately in response to a group of parents who sued a theater for barring their children from a showing of "Animal House." They had our permission to see it, even though we weren't with them, said the parents; besides, their suit pointed out, a Michigan law says businesses can't deny anyone "the full and equal enjoyment of goods, services . . . or accommodations of a place of public accommodation because of . . . age." Sorry, said the court: " . . . refusing admission of unescorted children to motion pictures designed for mature audiences is not only permitted but may actually be required to avoid civil liability."