She previously played for the Minnesota chapter of the Professional Women's Hockey Players Association (PWHPA).

[8][9][10] On December 30, 2024, she, alongside Hayley Scamurra, was traded to the Toronto Sceptres in exchange for Jocelyne Larocque and Victoria Bach.

[12][13] She was officially named to the US roster for the 2020 IIHF Women's World Championship before the tournament was canceled due to the COVID-19 pandemic.

[15] On January 2, 2022, Harmon was named to Team USA's roster to represent the United States at the 2022 Winter Olympics.

[16] Harmon has a degree in business innovation and entrepreneurship from Clarkson University and intends to pursue a Juris Doctor after her hockey career has ended.