Our Team
Rena Greifinger Managing Director, Experiential Philanthropy
Rena leads the Experiential Philanthropy division at Population Services International, including its signature programs Maverick Collective and the MaverickNext fellowship. With over 15 years of entrepreneurship, global health and design-thinking expertise, Rena has been at the forefront of designing and delivering unique philanthropic programs that drive lasting impact for women and girls around the world; while co-creating a movement of philanthropists who are becoming informed advocates, bold leaders and strategic investors through their partnership with PSI. As PSI's Global Youth & Girls Advisor for five years, she led the organization's work in design-thinking and private sector approaches to adolescent health. Prior to PSI she started Next Step's One Love Project, an award-winning program that builds leadership, life-skills and mentoring support for young people living with HIV in the U.S. She holds a Master’s of Science from the Harvard School of Public Health.
Nancy Anderson Senior Manager, Philanthropic Partnerships
Nancy manages philanthropic partnerships and supports the Next Gen strategy for Maverick Collective. Focused on the cross section of poverty alleviation and urbanization, she has worked closely with Fortune 500 companies to development critical social responsibility initiatives with an emphasis on social enterprise and leveraging technology for good. Prior to joining PSI, Nancy helped lead the corporate fundraising strategy at the American Red Cross and developed marketing partnerships for Huffington Post Media Group. Passionate about engaging women to take charge as leaders, she has volunteered at reproductive clinics across North Africa and led a young woman’s mentorship group at the Isleta Pueblo in New Mexico. She holds BAs from University of Missouri in Journalism and Political Science.
Darley Tom Manager, Experience
Darley Tom is a partnerships and communication expert with more than a decade of experience across the public and private sectors. As Program Manager for MaverickNext – a philanthropy accelerator for emerging women leaders to become informed advocates, bold leaders, and strategic investors in social impact – Darley leads on program execution and advocacy.
Prior to PSI, Darley led marketing and communications at Park Hyatt, public affairs efforts for the United Nations Foundation’s entrepreneurship and innovation portfolio including its Global Entrepreneurs Council, and worked under the Department of Management at the United Nations.
Darley is an author in the journal of Virology for her work on Hepatitis C and was awarded Best Annual Report and Brochure by PR News while at the UN Foundation. Darley holds a Masters in Sustainable International Development from the Heller School of Social Policy and Management at Brandeis University.
Lizzie Cohen Senior Associate, Experience
Lizzie leads communications and advocacy planning for the Maverick Collective. Prior to joining PSI, she brings almost a decade of experience across global health, advocacy & policy, communications, and strategic partnerships across the public and private sector. Her previous roles at PATH, Devex, and the AB InBev Foundation specialized in transforming new teams within organizations through internal communications initiatives and building visibility opportunities for leadership. Lizzie holds a BA in International Political Economy with a minor in Global Development Studies from the University of Puget Sound. Outside of work, Lizzie is a trapeze enthusiast.
Natalie Fellows Manager, Impact
Natalie supports in identifying projects in the pipeline for new Members with Maverick Collective as well as managing philanthropic partnerships with Maverick Collective members. Most recently, she worked for PSI on the Latin America and Asia Program Management Team, lending her support to PSI’s diverse portfolio of programs in Cambodia, Laos and Vietnam. Prior to joining PSI, Natalie served as a Health Extension Agent with the U.S. Peace Corps in Cambodia where she spearheaded a number of community-based projects in adolescent sexual and reproductive health, dengue fever prevention, and youth leadership. She has held philanthropic engagement and development roles at The Trust for Public Land, Creative Alternatives of New York, and The New York Botanical Garden. Natalie holds a MSc in Health, Community and Development from the London School of Economics.
Bridget Hanagan Senior Associate, Philanthropic Partnerships
Bridget supports the management of philanthropic partnerships with Maverick Collective members. She has worked closely with families and individuals to develop and execute their charitable giving goals and maximize their impact on the causes they care about most. Prior to joining PSI, Bridget worked as a Donor Services Officer for the Greater Washington Community Foundation managing a portfolio of donor advised, scholarship, and sponsored program funds, helping donors think more strategically about their philanthropy, leveraging their current giving to align with the organization’s programmatic objectives, providing issue area expertise to scale the impact of their gifts, and craft their charitable legacy. She holds a BA from Simmons University in International Relations and Economics with a French minor.
Caroline Tolbert Associate, Philanthropic Partnerships
Caroline supports the team and Kate Roberts as Senior Vice President in scheduling, events and budget management, handling the day to day operations of Maverick Collective. Prior to joining PSI, Caroline was an Account Manager at WeddingWire, a technology startup based in Chevy Chase, MD, where she engaged with event merchants to help them grow their businesses through best practices and the latest technology and industry trends. She holds a BA in communications from Towson University.