Shannon has a younger brother named Sean and her parents are Precious Garcia and Mark Mitchell. Her father is of Scottish and Irish descent and her mother is from the Philipines, specifically the province of Pampanga. Her mother made the move to Canada when she was 19. In an interview with Flare magazine, Shay revealed that she channeled aspects of her own mother for her role as Tina, stepmom to Jennifer Aniston’s character’s kids, in the film Mother’s Day.