In 2012, while playing for the Helensburgh Tiger Lillies, Bremner made her debut for New South Wales, scoring a try in a 10–34 loss to Queensland.[4] In July 2013, she was a member of Australia'sWorld Cup-winning squad, scoring five tries in a 72–0 win over France and a try in the final against New Zealand.[5][6]
In 2017, Bremner was a member of Australia'sWorld Cup-winning squad but missed the final due to injury.[7]
In June 2018, she joined the St George Illawarra DragonsNRL Women's Premiership team, being named captain.[8] In July 2018, Bremner represented New South Wales Country at the NRL Women's National Championships, winning the Player of the Carnival award.[9][10]
In Round 1 of the 2018 NRL Women's season, she made her debut in the Dragons' 4–30 loss to the Brisbane Broncos, scoring the Dragons only try. She fractured her toe in the loss, ruling her out for the season.[11]
In 2019, Bremner sat out the 2019 NRL Women's season due to the birth of her first child.[12] Instead, she joined the team's coaching staff as an assistant coach.[13]
In September 2022, Bremner was named in the Dream Team announced by the Rugby League Players Association. The team was selected by the players, who each cast one vote for each position.[16]
On the 19th of July, Sam announced that she would return to the Sydney Roosters after Corban Baxter did her ACL 1 week out from the season kick off.