Born on 9 May 1945, McDermit finished as runner-up in the women's foil at the 1965 New Zealand national fencing championships.[1] The same year, she was part of the New Zealand team that competed against Australia.[1]
At the time of the 1966 British Empire and Commonwealth Games, McDermit was working as a typist.[1] At those games, she represented New Zealand in both the women's individual and teams foil events.[2] She won a bronze medal in the individual foil,[3] and then won a second bronze alongside Pam French and Joyce Fenton in the team event.[4]