Weglyn was born on November 29, 1926, on her family’s farm in Stockton, California. She was one of two sisters and had a loving mother and father, Tomojiro and Misao Weglyn. Before going to school in the mornings, Weglyn fed the chickens and the horses to prove to her father she was just as useful as a boy. In 1926, boys were often considered more important than girls.