Who is Miss Chrissy Samson from Me Talk Pretty One Day and what is their importance?

Miss Chrissy Samson is Sedaris's fifth-grade speech therapist. She is clever, often trying to trick Sedaris into pronouncing words that will demonstrate his lisp. Her therapy sessions are a nuisance and embarrassment to Sedaris so he works diligently at developing a new vocabulary to avoid using S-words. In hindsight, these efforts may have contributed to Sedaris's future as a writer.