Academic Team

Rachel Shiderman (OCT, MT, Hons BES)
Principal

Rachel Shiderman earned an Honours Bachelor of Environmental Studies (Co-op) from the University of Waterloo, then a Master of Teaching from the Ontario Institute for Studies in Education, University of Toronto, where she dedicated her Master’s thesis to exploring the way teachers modify and adapt environmental programming for students with special needs.

Rachel first found her love for education in the outdoors, working in the K-12 space as an environmental education instructor for various outdoor education centres throughout the Toronto District and Durham Region school boards. She then began her classroom teaching career at The Dalton School, with a focus on K-8 Mandarin dual-language education, where over time she took on the role of English Department Head and eventually School Principal and Interim Head of School. In her most recent role, she supported the Principals and Vice Principals of The Bishop Strachan School, a K-12 private girls day and boarding school in Toronto, while leading the academic administration team through various process updates and school system advancements.

Rachel is a life-long learner who constantly seeks to better inform and add to her practice, collaborate with colleagues and extend herself to the interests of her school community, both in and outside of the classroom.

Stephanie Guerreiro (OCT, B.Ed, BA)
Guidance Counsellor

Stephanie Guerreiro completed her Bachelor of Arts (History) at Trent University, and received her Bachelor of Education from Queen’s University. She spent the first five years of her teaching career working with students in Nanjing, China where she was able to explore her love of travel and experience different cultures.

Stephanie became a member of Keystone’s faculty as a Geography and History instructor in 2017. From 2022 onwards, she has assumed the role of an Academic Coordinator. In this capacity, she works closely with students on their university and college applications, and is a constant resource for post-secondary planning.

Stephanie loves working with students from international backgrounds, as well as those from closer to home, as they all have stories and experiences to share that make the world more colourful and fulfilling. Her favourite courses to teach are History and Geography, as they give everyone in the class a chance to broaden their worldview and learn about the world around them.

Ece Ozturk (OCT, Hons MA, BMath)
IB Coordinator

Ece Ozturk completed a Bachelor of Mathematics together with a Bachelor of Business Administration. She also holds a teaching certificate as well as a Master of Arts in Educational Administration and Supervision, which she completed with honours.

Ece became part of the Keystone team in 2016, teaching Math, and transitioned into the role of an Academic Coordinator in 2022. She is committed to the day-to-day success of all students and is always available for meetings with them to ensure that their time at Keystone is both enjoyable and productive.

Ece is passionate to share her love of learning with her students. She wants to instil a natural curiosity in the minds of her students so that they can find strategies to navigate today’s fast-paced world. She believes teaching is the first step in making a difference in this world – therefore, she wants to share her knowledge and experience with her students, wherever she is.

Jesmy Sunny (B.Eng)
Teacher

Jesmy Sunny is an accomplished education professional with a rich tapestry of experience spanning eight years, dedicated to nurturing young minds and fostering a passion for learning. With a solid foundation in both engineering and Advanced Mathematics, her academic journey has equipped her with a unique blend of technical prowess and pedagogical acumen. Armed with a Bachelor’s degree in Engineering and a postgraduate degree in Computer Software, she brings a multidisciplinary perspective to the classroom. This fusion of expertise allows her to bridge the gap between theoretical concepts and real-world applications, empowering students with practical insights that resonate in today’s rapidly evolving technological landscape.

Sheron Prakasia (B.Ed, BSc)
Teacher

Sheron Prakasia is a passionate science teacher. She completed Bachelor’s degrees in both chemistry and education. She then completed her Master’s degree in chemistry from Mahatma Gandhi University, India.

Sheron strongly believes that education shapes an individual, not only in academics, but in their overall development. A teacher should help each child live in the outside world; teaching and learning is not something that is enclosed within books and school. Learning should be fun for students so that they will enjoy it instead of feeling burdened by it.

Sheron has experience teaching students with learning disabilities and she is ready to make any changes to her teaching style in order to achieve success for each child. She strongly believes that each child is important and that their learning needs have to be assessed regularly.

Steven Mesaros (Ph.D. ABD, MA, BA)
Teacher

Steven Mesaros earned an Honours Bachelor of Arts in Political Studies and a minor in Business from Trent University, then a Master’s in Political Science from York University, where he examined the restructuring of work in Canada since the 1980s. Steven has been working towards his Ph.D. in Political Science at York University, achieving All But Dissertation (ABD) status. His research focuses on the evolution of concepts like Economic Justice, Democracy, and Globalization, employing history and theory within the social sciences.

Steven’s extensive background in teaching began with a decade-long tenure in South Korea, teaching to students ranging from kindergarten to Grade 12. Since 2012, Steven transitioned to a role as a high school Social Science Instructor, teaching a diverse array of courses in high school, including Advanced Placement courses. He also served as a guidance counsellor, assisting students with their university applications to institutions in the United Kingdom, the United States, and Canada.

Since 2017, Steven has also been teaching at York University, holding positions as both a tutorial leader and course director. His teaching portfolio includes primarily first-year introductory courses in Social Science (Intro to Social Science), as well as upper-year courses in American Politics.

Rabab El-Ahmadie (BA)
Teacher

After completing her BA in Marketing, Rabab El-Ahmadie chose to pursue a career in education, joining her family’s business, one of the largest international schools in Jeddah. To gain the necessary experience, she began as a French teacher and coordinator for the French language program. Rabab is dedicated to helping students achieve fluency and confidence in French through interactive activities and personalized support. As she grew more confident, Rabab also took on the role of preparing the curriculum for the Art Department at Lycée Français de Jeddah. Since then, she has continued her journey in education and has been dedicated to this field for over a decade.

Rabab is also a dedicated Art teacher with a passion for fostering creativity and artistic expression among students. With 10 years of experience in the field, Rabab cultivates a dynamic and inclusive classroom environment where students are encouraged to explore their unique artistic voices. Rabab is excited about the opportunity to inspire the next generation of artists and looks forward to contributing to the vibrant artistic community at Keystone. She believes that every student has the potential to create something truly extraordinary and is committed to helping them realize their full artistic potential.

Lucas Fitch (OCT, MA, B.Ed, BA)
Teacher

Lucas Fitch teaches English at Keystone, and has over a decade of experience teaching subjects ranging from English to History to Geography. Originally from the East Coast, he was educated at the University of King’s College before graduating from the University of Toronto with a double major in English and Peace and Conflict Studies. After two years of teaching in Japan, Lucas returned to U of T where he gained a Master’s in English and South Asian Studies, and a B.Ed from OISE. At Keystone, he currently helps run the Garden Club.

Lucas loves to travel and loves to read. A dedicated, enthusiastic teacher, he’s passionate about helping students make connections between their classroom studies and the wider world, and loves the opportunities for life-long learning that teaching provides.

“The world is before you and you need not take it or leave it as it was when you came in.” – James Baldwin

Kristen Da Silva (B.Ed)
Middle School Teacher

With over 15 years of experience in education and a vibrant background as a Theatre Arts educator and practitioner, Kristen Da Silva brings a wealth of creativity and dedication to her teaching. Her international teaching journey underscores her commitment to inclusivity and her knack for addressing diverse learning needs. Kristen earned her Bachelor’s degree in Theatre Arts and Education from the University of the West Indies, blending her love for the arts with her passion for education.

Kristen’s involvement in theatre extends beyond the classroom. She has enjoyed performing in various plays and dance presentations and has written and directed school plays, infusing her teaching with a unique artistic flair.

Her qualifications include a TESL Teaching Diploma from the Canada College of Educators, along with professional designations such as OCELT and ICTEAL, showcasing her expertise in language teaching and her ability to connect with students from diverse backgrounds.

Kristen looks forward to continuing her journey as an educator here at Keystone School, where she is excited to bring her passion and expertise to inspire and empower the next generation of learners.