Gerrien brings extensive board experience and a keen social awareness, gained through her roles as a non-executive director at various public institutions. She serves as Chair of the Innovation & Digital Committee and a member of the Remuneration Committee at RvC Examenkamer, which independently oversees the quality of private-sector exams and examinations. Additionally, she is Chair of the Audit Committee and Chair of the School Fund at Marnix College. She also contributes as a member of the PE Committee at the Erasmus Governance Institute, Erasmus University, and represents the Member Council of VVAO, an association for women with higher education. In her non-executive roles Gerrien specializes in the portfolios of HR, legal & governance matters, and organizational development, serving as the chair of the audit and remuneration committee.

Previously, Gerrien was an elected member and Chair of the Selection Committee of the NCD Member Council, the Dutch Association of Commissioners and Directors. She also chaired the Remuneration Committee of the Supervisory Board at GAZO Foundation, a primary healthcare organization, and led the Remuneration & Selection Committee of the Supervisory Board at the Netherlands Leprosy Relief.