Tuominen played for the Espoo Blues and attended Makelanrinne Sports High School in Helsinki. As a member of the Espoo Blues, she won the Finnish Championship three times (2007, '08, '09). In addition, she played in the 2009 MLP Cup with the Finnish National Team. She was a member of the bronze medal-winning Finnish team at the Winter Universiades, February 2009 in Harbin, China. She also helped Finland win the Euro Hockey Tour in December of 2008. Other appearances for Team Finland include a number of events in 2008, including the Four Nations Cup in November and a series against Sweden in September. At Makelanrinne, captained the team after being named one of the school's top athletes of 2007 and '08. One of her teammates with the Espoo Blues was Emma Laaksonen.