It s hard to imagine Charlie Brown without his sister, Sally. When she was born, Charlie Brown was so overcome with joy that he told his friends, I'm a father! instead of saying he was a big brother! Soon he helps push her in the stroller, Linus teaches her how to hold a blanket, and Snoopy tags along as she crawls around the house! Best of all, Charlie Brown loves his sister no matter what. That's what being a big sibling is all about!