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 held positions within various Catholic groups, such as Katholischen Elternschaft Deutschlands, Catholic Scouts of Europe, Sozialdienst katholischer Frauen, and the Forum of German Catholics.