She made her feature film directorial debut with "Mary Goes Round", starring Aya Cash. She developed the screenplay at the Canadian Film Centre. It was screened in the Discovery section at the 2017 Toronto International Film Festival. The film centres on Mary, a substance abuse counsellor who loses her job after getting arrested for drunk driving. Returning to her hometown to visit her estranged father, she struggles to cope with the revelations that her father is terminally ill and that she has a teenage half-sister she has never met. For her work on the film, McGlynn won the Jay Scott Prize for emerging filmmakers from the Toronto Film Critics Association.