Giannerini spent two seasons as the head coach of the Oglethorpe women's lacrosse program. She inherited a Stormy Petrel team that had been established just two years before her arrival and which had gone 0-16 in 2014. Giannerini inspired a cultural shift in the Stormy Petrel program that resulted in the first postseason accolades in program history, as well as matching the program-high win total this past spring.

While at Oglethorpe, Giannerini coached five Southern Athletic Association All-Conference players, the first such honorees in program history, as well as 12 Academic All-Conference performers. Giannerini's 2015 squad also posted the highest combined GPA of any Oglethorpe team.

Giannerini came to Oglethorpe following a season as an assistant coach at Stevenson in her home state of Maryland. Giannerini helped the Mustangs to their first-ever MAC Commonwealth Conference title and the program's first-ever NCAA postseason appearance. Giannerini worked under US Lacrosse Hall of Famer Kathy Railey, serving as an offensive coordinator, goalkeeper coach and led the draw specialist team.

In her one season at Stevenson, Giannerini coached five All-Conference team selections, two All-Region players, and the Mustangs ended the year ranked 19th in the IWLCA Coaches' Poll.

Prior to her time at Stevenson, Giannerini was an integral part of the Rollins women's lacrosse program, first as a student-athlete and then as a graduate assistant coach with the Tars. Giannerini played for Rollins from 2009-11, becoming one of the most decorated women's lacrosse players in school history. In three seasons, Giannerini scored 154 goals and tallied 27 assists, totaling 181 points for the Tars; her 3.35 goals per game average ranks first all-time at Rollins, while her points and goal totals rank second all-time.

Giannerini was a three-time IWLCA All-American at Rollins, the first All-American in program history, while also earning IWLCA All-Academic honors all three years, as well as being a three-time first team All-South Region selection. Giannerini was a two-time captain under Head Coach Dennis Short, leading the Tars to a 34-12 record over her three seasons.

Following her playing career, Giannerini spent the 2012 season as Rollins' graduate assistant coach, helping the Tars to their first NCAA postseason appearance as the top-seeded team in the South Region. Five Tars were named IWLCA All-Americans during the 2012 season, and the team was recognized as an IWLCA Academic Squad.