From Wikipedia:

After her uncle’s death, Hepburn, Ella, and Miesje left Arnhem to live with her grandfather, Baron Aarnoud van Heemstra, in nearby Velp.[11] Around that time Hepburn gave silent dance performances that reportedly raised money for the Dutch resistance effort.[33] It was long believed that she participated in the Dutch resistance itself,[11] but in 2016 the Airborne Museum ‘Hartenstein’ reported that after extensive research it had not found any evidence of such activities.[34] A 2019 book by Robert Matzen provided evidence, based on Hepburn’s personal statements, that she had supported the resistance by giving “underground concerts” to raise money, delivering the underground newspaper, and taking messages and food to downed Allied flyers hiding in the woodlands north of Velp.[35] She also volunteered at a hospital that was the center of resistance activities in Velp,[35] and, according to Hepburn, her family temporarily hid a British paratrooper in their home during the Battle of Arnhem.[36][37] Matzen also claims that Hepburn carried messages for the Dutch Resistance, including to downed British paratroopers.[38]