Turnbull attended Shattuck-St. Mary's prep school in Minnesota. Current NHL player Nathan MacKinnon attended the school at the same time as her. As a junior, she appeared in 52 contests while gaining 60 points. With the team, won two national championships in two years.
The 2011–12 Wisconsin Badgers season marked her first with the club. In a match versus the Lindenwood Lady Lions on September 25, 2011, she scored her first career NCAA goal. She holds various UW records and holds the NCAA record for shorthanded goals in a season. She was the captain of the Wisconsin Badgers in her junior and senior year, and is a NCAA champion. She played for the Badgers for a total of four seasons, identifying herself in her Twitter account as having graduated in 2015.
CWHL
Turnbull helped the Calgary Inferno capture their first-ever Clarkson Cup championship in 2016. Contested at Ottawa's Canadian Tire Centre, she scored twice in an 8–3 victory over Les Canadiennes de Montreal. She would miss most of the 2017-18 CWHL season training with Team Canada for the Olympics, but returned in time for the playoffs. In 2019, Turnbull would win her second Clarkson Cup with Calgary. In May 2019, Turnbull joined the PWHPA after the collapse of the CWHL. She participated in the 2020 NHL All-Star Game with the Canadian All-Stars.
International
She participated with Team Atlantic at the 2009 Canadian Under 19 nationals. She participated in the shootout for Team Atlantic in the quarterfinals versus Team Ontario Blue in a losing effort. On two separate occasions, she attended training camp for the 2010 and 2011 IIHF World Women's under-18. For the 2011 camp, Turnbull was one of only two Nova Scotians who were invited. In 2016, she made the Canadian National Women's team and competed in the world championships in Kamloops, BC. She also played for Canada in the 2017 and 2019 World Championships, and was selected for the 2020 World Championships before they were cancelled due to the 2019-20 coronavirus outbreak. Turnbull was selected to the Canadian roster for the 2018 Winter Olympics in Korea. She would put up 3 points in 5 games, winning a silver medal.
