[2] She played three seasons with the boys' ice hockey team of East Greenwich High School in the Rhode Island Interscholastic League, during which she ranked among the Avengers' leading scorers.
Fontaine committed to playing with the Northeastern Huskies women's ice hockey program as a high school sophomore and she joined the team as an incoming freshman in 2017.
In the 2019–20 season, she notched 42 points in 38 games, leading all Hockey East defenders in scoring and ranking second in the entire NCAA Division I.
[10] Her elder sister, Alex Tancrell-Fontaine (born 1992), played NCAA ice hockey with the Garnet Chargers of Union College from 2011 to 2015.
Her younger brother, Gunnarwolfe Fontaine (born 2000), played college ice hockey with the Northeastern Huskies (2020–2024) and Ohio State Buckeyes (2024–25) men's programs.