Charlie Brown and Sally Brown are brother and sister. Sally often annoys and complains to Charlie Brown but they have a good relationship with each other. Unlike Linus and Lucy, Charlie and Sally Brown do not often fight but they do argue with each other from time to time.
Charlie Brown's opinion of Sally
On May 26 1959, Charlie Brown's sister Sally was born. Initially Charlie Brown doted on his baby sister, though she too became a thorn in his side as she grew up. Sally often pesters him for help with her homework. Charlie Brown stoically bears this, although sometimes he is able to let Sally dig her own holes without pulling him in with her. He occasionally firmly puts his foot down on truly unacceptable behavior, such as lying about taking a crayon from school or reading his letters.
Charlie Brown is often frustrated by Sally's laziness and her reluctance to do the right thing when she finds herself in difficult situations. His attempts to lecture Sally usually either go over her head or fall on deaf ears. However, Charlie Brown still always helps her when it comes to her homework, or bullies.
Sally's opinion of Charlie Brown
Sally usually refers to Charlie Brown as "big brother", having called him by his full name only on very rare occasions (and usually only in her early years in the strip). Although deep down Sally loves her big brother, she has never developed proper respect for him. She invariably ends up disappointed in him when he fails to protect her from being teased or threatened by bullies. However, Sally constantly relies on Charlie Brown to help her with her homework, which usually results in his doing her assignments for her.