Photographer Nina Leen joined LIFE magazine as one of the magazine's first female photographers in the mid-1940's, going on to produce over 40 photo spreads for the publication all the way through the late '60s. She photographed everything from squirrels in couture to the wild women of the GOP, but she tended to focus on youth culture, and young women particular. Above and below, check out her images of the Deen triplets (throughout the years) as well a selection from a series on "teenage life in 1944." So grab a vanilla milkshake, put on your finest bobby socks, and enjoy...