Sally Brown has blonde hair with a curly fringe. She wears pink or blue polka dotted dresses with matching colored socks and she also wears white shoes with black laces. In the winter, and most of the time in the later years of the strip, she switched to a shirt and pants. She has a "take it easy" approach to life, preferring to slide by while doing as little work as possible. Her favorite pastime is sitting in her beanbag chair watching TV.
Sally is in love with Charlie Brown's best friend Linus, and her infatuation with him first began on August 22, 1960, while her character was still a toddler. Early on, Linus took on something of a "mentor" role to Sally, teaching her about the ways of the world, tutoring her in the New Math, and even, on one occasion, demonstrating to her how to use a security blanket. In an early strip published soon after Sally's birth, proud brother Charlie Brown found Linus doing some complex calculations of the sort usually associated with physicists. When Linus had finished covering a whole wall with these calculations, he asked Charlie Brown if Sally would go out with him once she was older. However, when Sally began to follow him around and it became obvious that she liked him, Linus was visibly uncomfortable and began to try his best to get rid of her.
She calls him her "Sweet Babboo" (inspired by Schulz's wife Jeanie, who used to call him that), and when Linus says something Sally finds especially witty or intelligent (even - or perhaps especially - if it's an insult), she'll express her admiration by asking, "Isn't he the cutest thing?". Her crush is a frequent source of embarrassment to Linus, but he endures it stoically for the most part, although he is sometimes driven to yell in exasperation, "I'm not your Sweet Babboo!". On one occasion, Sally also referred to herself as Linus' "Sweet Babbooette" (to which Linus responded, "I've never heard of a 'Babbooette'!").