She traveled to Australia after graduating to play with the Burnside Lacrosse Club in Adelaide, then began coaching as a volunteer with their U-15 team. In that same year, she found herself growing the game in Germany. Former AU teammate, Tara Michael, invited her to coach at a summer camp in Hamburg, and this opportunity grew into a full-time coaching role with the Bielefeld women’s lacrosse team for the next three years.
After returning to the U.S. to coach at the Winchendon School in Massachusetts in 2010, Harmsen took on two more international ventures in the Netherlands and in Kenya. She spent time on the coaching staff of the U-19 Dutch Women’s National Team until 2015, then assisted the staff of the Kenyan U-19 Boys National Team through a connection with DBA Africa.
Harmsen is currently the co-Director of Institutional Equity and Diversity at Saint Ann's School, but has kept lacrosse as an active part of her life. She continues to shape the game on a global level as a member of the USA Lacrosse Foundation Board, helping solidify the sport’s upcoming return to the Olympic stage in 2028.
An amazing journeywoman, the seed to Harmsen’s exceptionally impactful career was planted at American.
“This journey [in lacrosse] started at AU with me knocking on the lacrosse coaches' door and asking if I could try out,” said Harmsen. “Attending AU and subsequently playing lacrosse transformed my life.”