She has been gaining attention for her acting abilities since she entered the drama program at Argyle Secondary, a high school that places a heavy emphasis on arts and performance. Cronin excelled in this creative environment graduating with a Best Actress Award, a bursary to continue studying acting, and the Performing Arts Award - an award designed to recognize one student each year who possesses outstanding ability in both drama and music. She was accepted into the Bachelor of Fine Arts Acting Program at the University of British Columbia, a program that auditions national and international applicants and selects only six women and six men per year. The successful applicants study acting intensely for three years and each student's position and continuation within the program is subject to review at the end of each term. Cronin graduated from this program at the top of her class and received outstanding reviews from both her professors and the Vancouver media.

Within six months of her graduation, Rachel was acting professionally with a lead role in the Bastion Theatre Company's production of 15 Miles Of Broken Glass at the MacPherson Playhouse, Vancouver Island's largest theatre. Since then, she has continued to work consistently in theatre, television, and film receiving outstanding support and reviews from members within these communities.

Cronin was preparing to launch her one-woman show, 'Different Drummer', which she wrote and was preparing to star in at the upcoming Vancouver Fringe Festival when she was contacted by NBC to play a character "who definitely marches to a different drummer" on their one hour primetime series, "Ed" (2000). With a regular role on Ed, the People's Choice for "Best New Comedy Series" and a one-woman stage show waiting in the wings, this striking young actress' career is rolling right on cue.