The Shining twins were played by a pair of real life twins named Lisa & Louise Burns. They doubtlessly hold the record for being actors most famous for being on screen the least amount of time. Neither made another film.
Revealing Behind-the-Scenes Photos from Stanley Kubrick’s ‘The Shining’
Stanley Kubrick and Jack Nicholson on the set of the Red Bathroom in The Shining. Interestingly, the angle Kubrick is setting up is not a shot in the film. My guess is that he’s shooting this insert, a shot ultimately not used in the film.