A native of Calgary, Alberta, Canada, Koss played in nine rounds during the 2019-20 season with a 76.89 scoring average before the season was suspended due to COVID-19. She had a best finish that season at the Aggie Invitational, tying for 14th overall with a six-over 222, helping New Mexico State to the team title. She didn't see the course during the 2020-21 season as she retained her eligibility with a NCAA COVID-19 waiver.

As a sophomore she played in 11 tournaments and 29 total rounds and carded a 78.8 scoring average on the year. She was a part of the New Mexico State squad that advanced to the NCAA Regionals, competing at the Cle Elum Regional. Additionally, in her second season she competed against the Redbirds at the Red Rocks Invitational, helping the Aggies to the team title, while placing in a tie for eighth place individually with an even par 213 (71 in all three rounds). She played in six tournaments as a freshman, including a season-low round of 72 at the Wildcat Invitational.

Before starting her career at New Mexico State she attended East Manning High School and won the junior girls title at the 2016 CN Future Links Western Championship after finishing runner-up at the event a year earlier. She finished in the top-10 at the Golf Alberta Junior Championships in 2016 and the CN Future Links Prairie Championship in 2016.