I Saw an Earlier Film, Same Subject, Same Title, But Records Don't Back Me Up!

Please help me! I remember seeing an adaptation of "My Left Foot" on TV sometime around 1971-1974. The specific scene I remember is as far as I know not in the 1989 (or 1990 according to this listing) film. In it, a young lady was undressing or partly undressing in view of Christy. The lady may even have been his sister. Christy became extremely upset by this and the lady had to try to calm him down. I KNOW I saw, what I saw, when I say I saw it, and I wouldn't very well mistake the title "My Left Foot." By the content of this scene it would seem to have been a drama. I can find no record of this adaptation whatsoever! Thanks for any help.