Ms. Guyer joined St. Mark's in 2019 as Associate Director of College Counseling. Guyer previously coached field hockey and lacrosse at St. Andrew’s School in Delaware and served as head coach of the varsity lacrosse team at Abington Friends School (PA) before coming to St. Mark’s. In 2004, she helped lead the St. Andrew’s varsity lacrosse team to a state championship.

A 2003 graduate of Harvard College, Guyer was a goalkeeper for the women’s lacrosse team and still ranks among program leaders in career and single-season saves. Before college, Guyer was a four-year participant in the USA Futures field hockey program in addition to earning all-league honors in field hockey and lacrosse and All-American recognition in lacrosse.

Originally from Philadelphia, PA, Guyer was thrilled to return to Massachusetts when she came to St. Mark's. When not coaching or college counseling, she serves as House Head of a III Form boys' dormitory, with help from her cat, Peanut.