The Felders only appear in book 32.
The Felders live around the corner from Claudia. Their home has a large living room witha grand piano.
Susan Felder is an eight year old with brown eyes and brown hair. She has been diagnosed as an autistic savant and seems to live in her own world. She does not communicate and does not like to be hugged or touched. She is a very talented musician and can sing with perfect pitch and can memorize songs instantly. Susan has also memorized the calendar and can tell what day of the week any date fell. Kristy is Susan's first baby-sitter and intoduces her to James Hobart who is her first "real" friend. Susan is going to be transferred to a school with a strong music program.
Mrs. Felder is pregnant with another daughter, to be named Hope. She and her husband had their baby tested for autism and the test comes back negative.