Mäkinen was born in Kiukainen[1][2] and began playing ice hockey at the age of four. She started playing with her brother and learned the game at a local ice hockey rink. She played on boys minor ice hockey teams until 2011 when she joined Team Oriflame Kuortane, the women's representative team of the Kuortaneen urheilulukio, in the Naisten SM-sarja (renamed Naisten Liiga in 2017).[3] In the 2012–13 season, her second with Team Oriflame, she posted 3.02 goals against average and a .917 save percentage.[4]
Rather than return to the NCAA, Mäkinen opted to remain in Finland for the 2015–16 season and played with Ilves Naiset.
Between 2016 and 2018, she played as the starter for Lukko Naiset in the Naisten Liiga and played with Lukko U20 A in the men's U20 Suomi-sarja. She was recognized as Naisten SM-saija Goaltender of the Year in 2017.
In May 2018, she announced that she was signing with Linköping HC in Sweden, taking over the starting position from the retiring Florence Schelling.[6]
After two seasons with Linköping HC, she left the club to sign with Leksands IF for the 2020–21 SDHL season.[7] In January 2021, she transferred to Brynäs IF and several months later signed a two-year contract with the club through the 2022–23 season.[8]
Mäkinen was chosen to play in the 2014 Winter Olympics as the third goaltender, a selection that she said took her by surprise.[3] She was again named to Finland's roster for the 2018 Winter Olympics.
On the question of hitting in women's hockey, she has stated that "right now it’s really hard for the refs to differentiate what ‘contact’ means. Maybe there could be room for changes in the rules to allow more body contact without it overtaking the game."[10]