Mrs. Halberstadt appears in iScream On Halloween. She lives in apartment 13B, which was said to be haunted. She lives there with her middle aged son and her kitten. She is also shown to dye her hair red and has a dislike of spiders. She may also enjoy tennis as she has a tennis racket. Mrs. Halberstadt is deaf and wears a hearing aid, but she always forgets to turn it on, so it seems like she is ignoring people. Sometimes she complains about people whispering, even when they are speaking at a normal volume. Carly and Freddie had their first encounter with her in the Bushwell Plaza lobby and the trio saw her again when they broke into her apartment for the iCarly Halloween Special webcast. Since then, she has not been shown and neither has she or this encounter been mentioned.
Mrs. Halberstadt is played by Estelle Harris.