The Taproot Foundation is a dynamic team of professionals with extensive experience working for a wide range of nonprofits and corporations. We share a vision and dedication to providing world-class services to nonprofits, volunteers, and community partners so that together, we can create a stronger society.



Interim CEO

Liz Hamburg

Sarah Mankowski is a seasoned Human Resource leader who has been successful in a variety of industries including consumer package goods, manufacturing, and financial services.  She had led large teams, managed the Human Resource aspects of complex integrations, and driven large scale change.  She leverages over two decades of experience working in premier organizations like Capital One, Kraft Foods, Eaton Corporations, and Pizza Hut to develop creative, client centered approaches for individuals and organizations.

Ms. Mankowski started Mindframe Consulting in 2016 to focus on helping companies build sustainable Human Resource and Leadership Development strategies that will help them deliver long term business results.  As a consultant, She has a knack for quickly building relationships, providing practical solutions to tough problems, and driving tangible results.  She has deep integration experience and is able to identify critical elements needed to bring organizations and people together.  As a coach, Sarah is direct and supportive, helping clients see possibilities in challenging circumstances.   She has a special interest in developing female leaders.

An active member of her community, Ms. Mankowski is involved in a variety of philanthropic efforts, including Girls on the Run and PAWS Chicago.  She has also been on the board of directors for the Taproot Foundation since January, 2013.  She stepped into the co-chair role for the Taproot Board in June of 2016.

Ms. Mankowski earned her BA from the Alma College in Psychology and Sociology. She also holds a Masters in Labor and Industrial Relations (MLIR) from Michigan State University.  In addition she is a certified executive coach through Georgetown University.


Chief Program Officer

Lindsay Firestone

Lindsay (Firestone) Gruber is a widely recognized authority on pro bono programs and cross-sector nonprofit capacity building. As Taproot’s Chief Program Officer Lindsay oversees the strategic development and implementation of Taproot’s award-winning pro bono programs including Taproot’s signature Service Grant program as well as the organization’s online pro bono platforms and its corporate pro bono program development through its Advisory Services practice. 

In her over 11+ years at the Taproot Foundation Lindsay has served as a leader across Taproot’s functions and markets and founded Taproot’s Advisory Services practice in 2008, building the initiative into the global leader in corporate pro bono program design. 

Lindsay is a frequent public speaker on cross-sector collaboration, nonprofit capacity building, CSR, and corporate employee engagement, and has authored and contributed to many best-practice thought leadership pieces in the field on topics ranging from pro bono and leadership development to best practices in effective program design and scaling. Lindsay holds a BA from Yale University and is an America Express Leadership Academy alumna.

Her favorite root vegetable is the delicious sweet potato.


Chief External Relations Officer

A recognized expert in pro bono service, Elizabeth has worked with companies, intermediaries and nonprofits in building, leading, and advancing the pro bono movement since joining the Taproot Foundation in 2009. With increasing demands on our nation’s nonprofit sector, Elizabeth is dedicated to bringing together corporate professionals and nonprofit executives to solve the infrastructure challenges that keep organizations from achieving full programmatic scale.

During her tenure at Taproot, Elizabeth has served as both the Executive Director for the Chicago office as well as the Vice President of External Affairs prior to taking on her current role. In addition she has launched Pro Bono Week a worldwide celebration of pro bono, brought the impact of pro bono to bear on critical issue areas facing our communities via new collaborations and partnerships, and introduced new programming on pro bono readiness and nonprofit capacity building.  

Prior to her work with the Taproot Foundation, Elizabeth founded 20% Theatre, an all-women’s theatre company dedicated to addressing the inequity of women and power imbalance in the theatre arena. Elizabeth served as Artistic and Producing Director of 20% Theater from 2003-2010 producing shows including the world premieres of The Whole World is Watching and Tester.  

In addition, Elizabeth works as a consultant (pro bono and otherwise) with the Benevolent Group a consulting practice dedicated to innovation, exploring different avenues of program approach and positioning and changing the conversation to achieve crucial social goals. The Benevolent Group was founded by the members of Benevolent a digital nonprofit that introduced new ways in addressing issues of income inequality through connection and giving.   

Her 15+ nonprofit fundraising career spans some of Chicago’s most prominent arts and social justice organizations. Elizabeth is an alumni of the American Express Academy of Leadership and holds a BA from Smith College in English and Theatre. 

Her favorite root vegetable is the jicama.


Chief Finance and Administration Officer

Eos came to Taproot because she loves the impact created when organizations that do good harness the professional prowess of business experts. She spent many years using her professional skills for good and is still on the boards of a few school groups, such as the Parent Teacher Student Association (PTSA) and school site councils, as well as other nonprofit organizations. Through that work, Eos has seen firsthand how using skills-based volunteering and pro bono service can propel organizations forward.

Her educational background includes a BS in management, an MBA in corporate finance, and many hours of on-the-job training with cutting-edge employers. Eos brings Taproot over 15 years of experience in finance, HR, and operations at organizations such as the Rainforest Action Network, and the Mission Hub which runs a network of five Impact Hubs. Eos loves the variety of work and challenges that comes with her three-hat role. When she’s not rearranging spreadsheets, having deep HR conversations, or physically fixing a network issue, you can find her on a soccer field near you.

Eos’ favorite root vegetable is the humble carrot, although she is starting to learn to love the seductiveness of beets of all colors.