Does anyone know what movie this might be?

When I was a kid (way way back in the 80s ;P) there was this science fiction movie. It involved, I believe, a girl and a boy and they went somewhere and remade their grandmother or mother (I can't remember which) There involved a marble or something for her eyes maybe. I know this isn't very specific but if anyone knows about it or the name of it please let me know. My friend and I seem to be the only ones who remember this movie (and we grew up far away from each other so we know we're not imagining it) and we're starting to think we were the only two people in the entire world who saw the movie. Also, we both remember seeing it on TV so it might be a made for TV thing.... Thanks for any help.