In the late 1960s, at the encouragement of her brother-in-law, Hobbie sold distinctive artwork of a cat-loving, rag dress-wearing little girl in a giant bonnet to American Greetings in Cleveland, Ohio. The artwork, based on Hobbie's own children and with rustic New England style of a bygone era, became popular, and her originally nameless character (identified earlier as "blue girl") became known as Holly Hobbie. As a contract artist, Hobbie worked with the Humorous Planning department at American Greetings under art director Rex Connors, who was responsible for launching "blue girl" as the most identifiable of the Hobbie characters.