In the notable feminine side of the Stinson family, Katherine was first to take up flying. Flying lessons cost her $500, and the family piano was sold to help pay for them, but she never needed the piano again. She was the fourth woman in the U S to earn a pilot’s license, which she did on July 24, 1912 in a Wright B. Only 21 at the time, and tipping the scales 101 pounds, she became known as the "Flying Schoolgirl," flying exhibitions all over the country, even adding lights and doing loops at night. She set many records, performed in Japan and China, and was the first woman sworn in by the Post Office as an air mail carrier.

In 1915 Katherine and Marjorie instructed in their own Aviation School in San Antonio with their brothers, Eddie and Jack, as mechanics. There they trained Canadian cadets for the war, who became known as the "Texas Escadrille," and Marjorie was called the "flying schoolmarm." The girls also flew many exhibitions for the Liberty Loan Drive.

The Stinson School closed in 1917. Katherine became an ambulance driver for the Red Cross in Europe, where she contracted influenza, which eventually turned into tuberculosis in 1920, causing her retirement from aviation. She married in 1928 and moved to Santa Fe NM, where she designed houses. She was 86 when she died in 1977. (K O Eckland)