Staff and Board
Meet the Staff of Ambleside Schools International.
Staff and Board
Meet the Staff of Ambleside Schools International.
Let us never lose sight of our aims. Work together, let each one labor to produce a human being at his very best, and what a difference those children will make to the world in the future. It is impossible to put limits to the power and influence of even one good man or woman, so that any one of you, by laying herself aside utterly for a single child, may bless the world in unimaginable ways.
— CHARLOTTE M. MASON —
Let us never lose sight of our aims. Work together, let each one labor to produce a human being at his very best, and what a difference those children will make to the world in the future. It is impossible to put limits to the power and influence of even one good man or woman, so that any one of you, by laying herself aside utterly for a single child, may bless the world in unimaginable ways.
CHARLOTTE M. MASON

About Ambleside Schools International

Dean Peterson
Executive Director
The animating vision of Dean Peterson’s career has been mentoring others and utilizing his leadership and strategic skills to advance mission-driven causes. A long-time veteran of Capitol Hill and the nonprofit world, Dean served as Chief of Staff for three different Members of Congress and headed up the communications and advocacy efforts at the Hazelden Betty Ford Foundation, a nationwide addiction treatment provider, among other professional roles.
With the encouragement of the Ambleside Schools International Board, Founders Maryellen and Bill St. Cyr had prayed for years that the Lord would raise up an operational and strategic leader to enable them to transition into roles that emphasize writing, speaking, and mentoring. That prayer was answered in 2020 when Dean joined the organization to take it and its commitment to an Ambleside Education model to the next level.
Dean has a proven track record of success building and improving organizational operations. He is also a servant leader who believes deeply that the essence of our spiritual life is a close relationship with a personal God who is intimately interested in all aspects of our lives, especially our suffering. Dean and his wife of 30 years, Lyle, live in Falls Church, Virginia. They have three grown children in their twenties, and their youngest child is in college.

Maryellen St. Cyr
Founder,
Director of Curriculum,
Member, Board of Directors
By 1989, dissatisfied with the state of contemporary Christian education, Maryellen began to search for a philosophically and pedagogically consistent method of Christian education. She found just such a method in the writings of British educator, Charlotte Mason. Maryellen has since become one of the country’s leading experts on Charlotte Mason’s pedagogy and was a primary author of the book, When Children Love to Learn.
In 2000, Maryellen founded Ambleside School of Fredericksburg, Texas, providing children with a Charlotte Mason education and serving as a center for training interested educators from around the world. In response to growing requests for help in establishing Ambleside Schools, in 2005, Maryellen co-founded Ambleside Schools International.
Over the last two decades, Maryellen has mentored and trained hundreds of principals and teachers in Charlotte Mason’s philosophy of education and pedagogical methods. Maryellen is co-founder and currently serves as Director of Curriculum for Ambleside Schools International.
Maryellen St. Cyr has been a professional educator for more than 40 years, holding a M.Ed. in Curriculum Development.

Bill St. Cyr
Founder,
Director of Training,
Member, Board of Directors
The unifying mission of Bill St. Cyr’s academic, professional, and personal life has been the nurture of persons towards intellectual, psychological and spiritual maturity. He holds a B.A. in political philosophy from Louisiana State University, a M.A. in theology from Catholic University of America, and a M.S./Ph.D. in pastoral counseling from Loyola University Maryland.
Bill has served as a youth minister, led a discipleship ministry on Capitol Hill, served as assistant to the chaplain of the United States Senate, and spent thousands of hours as a professional counselor supporting committed believers whose lives have been something less than love, joy, peace, patience, and kindness.
In 2001, Bill joined his wife, Maryellen, in the Ambleside work, initially serving as a high school teacher at the first Ambleside School. Since co-founding Ambleside Schools International, Bill has dedicated himself to supporting and equipping principals and teachers across the Ambleside network. He currently serves as Director of Training for Ambleside Schools International.

Shannon Seiberlich
Director of Community Relations and Homeschool
Shannon first began reading Charlotte Mason’s volumes and practicing this educational philosophy as a homeschooler over 20 years ago. When her children were in middle school, she enrolled them at the Ambleside School in Virginia and was invited to join the teaching staff at the school.
As an Ambleside teacher, Shannon taught Art and grades 2, 3, 4, 7, and 8 over ten years. While on the Ambleside Schools International staff she has also provided support with community relations and communication, teacher support materials and training, and social media. Shannon has had the privilege to serve as a mentor for Ambleside Homeschooling member families since 2004 and is now Director of Ambleside Homeschooling.
Shannon graduated with a B.A. in Advertising from the Pennsylvania State University School of Journalism and worked in her field of study as Media Director for a DC ad agency for many years. She has volunteered as an usher at the Folger Shakespeare Theater and had the privilege of being on the planning team for the baby shower given to the 911 widows in NYC on the 1-year anniversary. Her other interests include exploring new places, craft coffee, photography, writing, cycling, researching, and collecting old books (and reading them).

Leslie Voorhees
Director of Member Schools
Leslie Voorhees’ vocational calling solidified as she found the writings of Charlotte Mason while in pursuit of providing a life-giving education for her children and community. With over two decades of experience with Charlotte Mason’s philosophy of education, she has served in many roles: Co-founder of Ambleside School in McLean, VA; board chair; classroom teacher; and currently serves as Director of Member Schools for Ambleside Schools International.
Prior to becoming a mother of three Ambleside students, she worked as a regional director for Estee Lauder Companies, served on several boards of faith-based schools and organizations, and received her B.S. in Biology and Health from the University of Richmond.
In 2013, Leslie joined the ASI team as a teacher trainer and curriculum writer. She has focused her attention on onboarding and mentoring new Ambleside Member Schools. Her greatest delight is in spending time with her three grown children and their families, spread between Virginia, Colorado, and Arizona.

Thomas Costello
Director of Administration
The journey of Thomas Costello’s professional career has been focused on supporting and encouraging others while maintaining a growth mindset for both the individual and organization. He holds a B.S. in Accounting from Western Governors University and received CompTIA Project+ Certification in 2015.
Thomas first began learning about Charlotte Mason in 2010, when his nephews attended Kindergarten at the Ambleside School of Ocala. Through interactions with his nephews, other students, and school events, he started to understand the beauty of a Charlotte Mason education. In 2019, Thomas joined his wife, Terri, at Ambleside School in McLean, Virginia, where he served as the Director of Administration. His role expanded in 2021 to include teaching 8th grade Algebra I.
While serving at Ambleside School in McLean, Thomas led the school’s transition to a new student information system, allowing all admissions, enrollment, and progress reports to be processed and stored online. Thomas also developed and supported the use of an information-sharing platform to maintain documents and historical school information. Thomas’s experience with school infrastructures will be invaluable as he serves Ambleside Schools International. Thomas and his wife, Terri, live in Marion, IL.

Michael Reyes
Director of Development
Ministry has been part of Michael’s life since age 13, when he began serving with his father on the weekly worship team. He went on to serve as a volunteer and later staff member with YoungLife for over a decade, where he developed his knowledge of fundraising and a heart for developing environments where children and youth can come to know God better.
With YoungLife, Michael helped develop ministries, disciple high school and college leaders, and raise funds across Houston. Desiring to gain more leadership, sales, and marketing skills, he then transitioned to the Enterprise management training program where God grew him immensely as a leader. For the last seven years, Michael has been named among the top salesman, garnering awards for his accomplishments with Enterprise and Thryv software sales.
Michael and his wife, Caitlin, have two daughters: Ila and Ivy. They decided to make the move from the big city of Houston to rural Southern Illinois where they were pleased to discover Ambleside School of Marion. They’re so thankful God not only led them to this great school for their children, but that God opened the door for Michael to bring his expertise in advising, fundraising, and training to this incredible organization and mission.
Michael will be engaging and stewarding Ambleside Schools International’s many relationships that provide the resources to inspire, train, and equip a global community in promoting a living education.

Zach Ward
Trainer
Zach has a strong desire to participate in the Ambleside movement centered on bringing a Charlotte Mason education to communities around the nation and globe. He has a B.A. in Biology, an M.Ed. in Curriculum and Instruction, and more than twenty years of teaching experience in both the public sector and in private, faith-based schools.
Zach was first introduced to what Charlotte Mason calls a “twice-blessed” education in the fall of 2010. He attended ASI’s Summer Institute, at which he was introduced to Mason’s philosophy and pedagogy. Over the past decade, he has been challenged by the idea of what it means to “come to know” and is excited about walking beside school communities, teachers, and students as they desire to grow in this life-giving approach to education.
In 2015, Zach and his wife, Cheryl, moved to Holland, Michigan to lead Calvary Schools of Holland’s transition to a Charlotte Mason education. He completed ASI’s Master Teacher Training Program in 2020 and currently serves as a lead teacher trainer at ASI’s Summer Institute; he also travels within the ASI network to provide training and support to member schools. He currently serves as Calvary’s Director of Instruction.
About Ambleside Schools International