Stephie Robertson is an 8-year-old girl from Palo City, California that Mary Anne Spier baby-sat for during the BSC's visit to California & she bonded with her.

Her mother died when she was young and her father is described as overprotective. Stephie has asthma due to emotional distress. She uses an inhaler & pills to treat her medical condition.

Stephie used to be painfully shy, but has started coming out of her shell, befriending her new neighbor, Margie. She loves reading & and is described as an excellent reader.

She has a nanny named Joanna, who usually baby-sits for her. Her morning baby-sitter is Lisa Meri.

Stephie's bedroom is described as young-looking with pink bunnies everywhere & pictures of storybook characters on the wall. She wrote a story called "The Special Flower" in which Dawn Schafer as a surrogate mother-type.

She lives near the DeWitt family and goes to school with Erick & Ryan DeWitt.