In 1949, illustrator Harry Anderson did a series of covers for Woman's Home Companion featuring a blond-haired brother having fun with his brunette sister.
Anderson was a specialist in painting children for the women's magazines. The covers in this series are consistently well drawn and full of Anderson's generous and playful spirit.
Harry Anderson (1906-1996) painted in gouache or casein because he was allergic to oil. If you want to see more examples of his work, check out the online collection by Jim Pinkoski.