Masson began her academic teaching career in the United States, first at Whitworth College then at Calvin College, Grand Rapids, Michigan. She was formally installed as the college's tenth Principal during a service at
Durham Cathedral in May 2016. Masson was a board member and trustee of
Traidcraft for many years, a member of the Leech Professorial Management Board, a member of the board of
Ridley Hall, Cambridge, and is a Bishop's Reviewer for Ministerial Training in the
Church of England. ==Personal life==