Westphalen was a member of Katholischen Elternschaft Deutschlands, Catholic Scouts of Europe, and Sozialdienst katholischer Frauen. She also served as a member of the board of trustees of the Forum of German Catholics.
Westphalen participated in several organizations, including the Catholic Parents' Society of Germany, European Catholic Scouts, and the Social Service of Catholic Women. She was also a member of the board of trustees for the Forum of German Catholics.