Laura Dern's Second Movie
Laura Dern was uncredited in both of her first two movies.
She was 6 or 7 when this movie was being filmed and she played an extra at the lunch counter in the diner when Kris and Ellen were having their biggest scene towards the end.
She's Diane Ladd's daughter so I guess she was around and Martin Scorsese asked her to be an extra ("Girl Eating Ice Cream Cone"). The takes went on for so long that she ended up eating 17 ice cream cones without throwing up.
It's why she decided to be an actress.