Netherlands
Hepburn's mother believed England would soon be occupied by the Germans, so the family moved to the Netherlands. While she knew the basics Audrey was forced to become extremely fluent the Dutch language quickly in order to blend in. She used the name Edda van Heemstra to hide her English heritage. There, she aided the Allies by putting top secret notes in her shoes and delivering them to the Dutch resistance.
Dance
To further help the Dutch resistance, Hepburn's mother enrolled her daughter into the Arnhem Conservatory where she studied ballet. There the Conservatory would put on underground dance recitals to raise money for the Allies. Hepburn was quite skilled for her age and could've been a prima ballerina. However, her ballet teacher commented that her height of 5ft 7in would hinder her from ever realizing her dream, an insecurity of Audrey's that carried throughout her life. If you pay attention to her footwear in her movies, Hepburn is often sporting ballet flats in order to make her opposites appear taller.