Feryn played the lead role of Marie Boesman in the drama In Flanders Fields by Jan Matthys. Her character is a 15-years old girl who quickly matures amidst the horrors of the First World War. She was cast in 2011 and performed the role in 2012. The ten-part series aired in January 2014 on the VRT-owned Eén. Based on the series, she wrote the book Dagboek van Marie (Diary of Marie), published in 2014 by Manteau. Her second book, Dagboek van Marie : Brieven van Marie verschenen (Diary of Marie: Letters of Marie) was published in 2014.