Saoirse-Monica Jackson Erin Actor Louisa Harland Orla Actor Nicola Coughlan Clare Actor Jamie-Lee O'Donnell Michelle Actor Dylan Llewellyn James Actor Kathy Kiera Clarke Aunt Sarah Actor Tara Lynne O'Neill Ma Mary Actor Siobhan McSweeney Sister Michael Actor Tommy Tiernan Da Gerry Actor Ian McElhinney Granda Joe Actor Leah O'Rourke Jenny Joyce Actor Beccy Henderson Aisling Actor Claire Rafferty Miss Mooney Actor Damien Molony Gabriel Actor Art Campion Father Peter Actor Maria Laird Wee Tina Actor Lisa McGee Writer, Executive Producer Michael Lennox Director Caroline Leddy Executive Producer Noel Hogan Music Brian J. Falconer Producer Liz Lewin Executive Producer Jimmy Mulville Executive Producer