Tollerød started school at 7. She was always active outside of school and enjoyed horseback riding, skiing (cross country), European handball, aerobics, and singing. She has one younger sister named Susanne.
She was discovered by scout Donna Ioanna while Christmas shopping at H&M in Sørlandssenteret shopping mall. Tollerød went to Milan, Italy in September 2006 to dabble in modeling for a summer. She soon returned home to earn her high school diploma. Immediately upon graduating, she signed with Trump Models and was asked to shoot for Vogue Italia with Steven Klein. She moved to New York City in April 2007 to pursue full-time modeling and, within that first year, she was featured in a DKNY campaign, opened and closed the spring D&G shows, was on the cover of 10, and shot Prada Sport with Steven Meisel. In October 2009, Tollerød switched mother agencies from Trump to DNA Model Management.