The Foster family is the human family that raised and took care of Sophie. They believed Sophie was their biological daughter and did not know that she was an Elf or telepathic. They no longer remember Sophie however, because they had their memories wiped on Sophie's request. Sophie wanted them to forget her so they wouldn't have to live with the pain of believing their daughter died. (The Elves had planned on faking Sophie's death so that she could come to live with them secretly).
Amy- Sophie's younger sister who liked to tease and annoy Sophie a lot. She has dark hair and dark eyes, much like her parents and unlike Sophie. She is described as popular with average grades, the polar opposite of Sophie when she lived with them.
Sophie- (see Sophie Foster)
Marty- their cat