Kathy Steinberg is a former child actress who provided the voice of Sally Brown in four Peanuts television specials: A Charlie Brown Christmas, Charlie Brown's All-Stars, It's the Great Pumpkin, Charlie Brown and You're in Love, Charlie Brown.
During production of A Charlie Brown Christmas, Steinberg had not learnt how to read, so her lines were fed to her, a word or syllable at a time.
During production of It's the Great Pumpkin, Charlie Brown, Steinberg had almost finished recording all her lines when the producers got a phone call from her mother letting them know that one of Kathy Steinberg's teeth was loose. Fearing that a sudden lisp would ruin continuity, the producers rushed Steinberg into the studio to finish up recording her lines. As Steinberg was speaking her last line, her tooth came flying out of her mouth.