Actress feared Channel 4 comedy might miss the mark at home Saoirse-Monica Jackson (Photo by Taylor Hill/WireImage) Saoirse-Monica Jackson was relieved people in her home city loved Derry Girls because she knew they would not have minced their words if they had hated it. The 31-year-old actress shot to fame playing schoolgirl Erin Quinn in the Channel 4 comedy, and has gone on to star in other shows, including The Flash and the new Netflix series The Decameron..