Collier was presented with the American Shakespeare Festival Theatre Award for distinguished service in training and guiding actors in Shakespearean roles. Collier was a drama coach for many famous actors, including Audrey Hepburn, Vivien Leigh and Marilyn Monroe. She also coached Katharine Hepburn during Hepburn's world tour performing Shakespeare in the '50s. Upon Collier's death in 1955, Hepburn "inherited" Collier's secretary Phyllis Wilbourn, who remained with Hepburn as her secretary for 40 years. Collier has a star on the Hollywood Walk of Fame. Collier died of a heart attack in Manhattan on 25 April 1955 at the age of 77.