Upper School Teachers

Robert Loren Thoburn

History, Government, Economics
OH Since 1997

Robert and his wife, Sheila, attend Reston Bible Church. In 1997 they founded OH and have seen 6 of their grown children graduate from the school. Their 3 youngest still attend. Robert earned a B.A. in business and Austrian economics at Grove City College and a J.D. from Pepperdine University School of Law.

David Sabin

PE, History, English, Bible
OH Since 2016

David Sabin teaches junior high history, English and Bible as well as directs the upper school P.E. program. He has a passion to see each of his students succeed both academically and spiritually. Raised in a missionary family, he spent many years abroad and is fluent in Spanish. Mr. Sabin holds a B.S. in English and Spanish Education and an M.A. in Administration from Pensacola Christian College. He and his wife are blessed with four sons.

Seth Thoburn

Latin
OH Since 2018

Seth Thoburn enjoys just about any language: Latin and Hebrew as well as math and programming which he also considers to be languages. Seth is a full stack developer at ConsignCloud and graduated cum laude with a B.A. in Liberal Arts and Culture from New Saint Andrews College.

Zachary Aardsma

Math, Science
OH Since 2021

“Mr. Z” teaches high school math and science. He studied molecular biology at the University of California, Santa Cruz and Houghton College. He enjoys tennis, mountain biking, golf, pickleball, swimming, drawing, and painting. He and his wife attend Cornerstone Chapel, and they just welcomed their first baby girl in September.

Sheila Key Thoburn

Literature and Writing
OH Since 1997
IEW Registered Instructor

Sheila Key Thoburn has been instrumental in shaping Oak HIll’s classical curriculum. A native of Arlington, she studied Early Childhood Development at Pellissippi State and brings both warmth and whimsy to the classroom. A lifelong lover of books, Sheila also enjoys writing and regularly shares her thoughts on education on the school blog. She is a registered instructor with Institutes for Excellence in Writing and has taught IEW methods for over 15 years.

Claudia Key

Music
OH Since 2005

A native of Northern Virginia, Claudia Key grew up in Christian schools. She studied voice, piano and art. Mrs. Key speaks fluent Spanish and is a very engaging teacher. She has 4 children, 4 grandchildren and attends Reston Bible Church with her family.

Arelis Gil

Athletic Director, College Counselor
OH Since 2014

Arelis Gil earned a B.S. in Education and an M.Ed. in Curriculum and Instruction from the University of Nevada, Las Vegas. She spent six years as an instructor at Palo Verde High School in Las Vegas and has experience teaching honors history, AP and other courses. She has 3 children at OH and attends Centreville Baptist Church.

Tessa Wemlinger

Junior High Science
OH Since 2024

Tessa Wemlinger brings a love of nature and a heart for hands-on learning to Oak Hill’s science program. She has homeschooled her four children for fourteen years, but this year decided to make a change in her youngest daughter’s education, and both joined the Oak Hill community. Tessa continues to teach middle school science at her homeschool co-op while alternating teaching days at OH. She delights in engaging students with creative, hands-on lessons that inspire a true wonder for God’s creation.