Sheil was raised in Jersey City, New Jersey. She studied at New York University's Tisch School of the Arts, graduating in 2006 with a B.F.A. in acting. She also studied acting at the Lee Strasberg Theatre and Film Institute.
In 2016, after her film Kate Plays Christine premiered at the Sundance Film Festival, she was dubbed "the Meryl Streep of the micro-budget film community" by Rolling Stone.
