Our Team

NVMS Staff Members

Arleen Ramirez Borysiewicz, MPA, She/Her/Hers
Executive Director
Office hours: 9:00am-5:00pm, Monday-Friday
703.865.7260, aborysiewicz@nvms.us

Arleen has 25+ years of nonprofit experience, with expertise in management, fundraising, external affairs, community relations, board development, and branding and marketing. She served as chief fundraising executive for several nonprofit organizations including United Community, a direct service agency supporting low-income families in Alexandria, Virginia; Ayuda, a Washington, D.C.- based legal immigration services nonprofit; and The Washington Center for Internships and Academic Seminars, also based in Washington, D.C. Arleen earned her Master of Public Administration from The George Washington University. She holds professional certifications in nonprofit management from Georgetown University, and in association management and diversity and leadership from the American Society of Association Executives. Arleen is an ex officio board member of NVMS Conflict Resolution Center, and serves on the board of directors Resolution Virginia. She is also a member of the Ayuda Advisory Council.


Guillerma Calles, She/Her/Hers
Family Mediation Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703.865.7263, gcalles@nvms.us

Guillermina is not new to NVMS Conflict Resolution Center. Before her hire as Family Mediation Coordinator, she was Operations Coordinator since November 2021. Her training in the NVMS Basic Mediation Skills and Process course in 2021 and recent assignments to support family mediation screening and intake work make this transition seamless. Her Spanish language fluency has allowed NVMS to address the needs of Spanish-speaking community members calling for assistance, with care and clarity about disputes that they face. In February 2023, Guillermina earned her Supreme Court of Virginia GDC Mediation Certification. Her next aspiration is to earn certification in family mediation. Guillermina received her law degree from the Universidad de Belgrano, Facultad de Derecho y Ciencias Sociales in Buenos Aires, and she earned her LLM in international legal studies from American University, Washington College of Law.


Taylor Piepenhagen She/Her/Hers
Restorative Justice Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703-639-4378, tpiepenhagen@nvms.us

Taylor developed her understanding of restorative justice as Asset Protection Officer at Target, where she influenced and validated the safety culture of the store and led emergency response and crises events. She was a public safety and law enforcement officer at American University, as well as worked in the university Housing and Residential Life and Office of Campus Life, where she served on the Student Conduct Council and Conflict Resolution Services. Taylor received a Bachelor of Arts in International Studies, with a concentration in Peace, Conflict Resolution, and Foreign Policy, at the American University School of International Service.


Mark Preston, He/Him/His
Training Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703.865.7261, mpreston@ablattnvmsus

Mark retired from the U.S. Army in 2022. He has completed all the coursework for the Supreme Court of Virginia mediation certification. He also had served as a neutral on U.S. Department of Defense employee issues. We thank Mark for his military service. And we appreciate that he has chosen NVMS Conflict Resolution Center for the next chapter of his career.

Mark is an innovative, strategic, and goal-oriented leader, and we look forward to having him fortify our training program. Mark received his Master’s degree in legal studies at Washington University in St. Louis.  mpreston@nvms.us


Lydia Ray, She/Her/Hers
Court and Community Mediation Coordinator 
Office hours: 9am-5pm, Monday-Friday
703.865.7262, lydia.ray@nvms.us

For more than seven years, Lydia Ray has been utilizing her skills in alternative dispute resolution while expanding her knowledge and experience in conflict resolution in both domestic and international settings. Lydia is a Supreme Court of Virginia certified Juvenile and Domestic Relations and General District Court mediator. She had additional training in domestic violence assessment, ethics in mediation, mediation and communication, and restorative justice circles. Prior to joining NVMS Conflict Resolution Center, Lydia operated her private practice, Guided Mediation LLC, in Fairfax, Virginia. It is a family and community mediation practice that facilitates mediation sessions for families and individuals. She was the lead facilitator in guiding families through divorce and separation through the alternative dispute resolution process of mediation and conflict coaching sessions. She offered monthly blogs on topics related to conflict coaching, alternative dispute resolution themes and holistic approaches, tips and techniques of which Burnout and Vulnerability for the Win! have been featured on Mediate.com. Lydia earned a Bachelor in Global Affairs and Conflict Analysis from George Mason University. 


Aaliyah Zagade, She/Her/Hers
Training Programs Assistant

Office hours: 12 noon-5pm, Tues-Wed-Thurs
703.865.7272, azagade@nvms.us

Aaliyah Zagade is a student at George Mason University, pursuing a bachelor’s degree in conflict analysis and resolution with a concentration in political and social action. She is a member of Pi Gamma Mu Honor Society and the National Society of Leadership and Success. Her role as a research assistant for the Better Evidence Project at George Mason University has allowed her to explore global peace building practices by sourcing resources that illustrate effectiveness in peace building and conflict prevention. Additionally, she has gained valuable experience in the legal space through her judicial internship at the United States District Court for the Eastern District of Pennsylvania, where she developed a comprehensive understanding of legal research and writing, court proceedings, and the judicial system. Aaliyah is committed to making meaningful contributions to the field of conflict resolution and wants to make a positive societal impact.