Conversation so far:
Who was the double agent?
Professor X is forced to make Mystique his secret agent, as his previous one, Prudence Leighton, has died and Mystique is the only one suitable to complete the missions.
Who did Mystique turn on to become a double agent?
Quiet Man

Question: Was she forced into this decision?
Self-contained rewrite: Was Mystique forced into turning on quiet man?