Lower School

Amy Rangel

Amy Rangel has her Master’s degree in Interdisciplinary Studies with an emphasis on Child Development. She worked at Children’s Medical Center for 11 years as a Child Life Specialist. She also teaches at Brookhaven Community College in the Child Development/Teacher Preparation Department. She has been at Vanguard since 2015.

Devin Warren

Devin Warren graduated from the University of North Texas with a Bachelor’s in Social Work and a minor in Family Studies and Child Development. Devin loves working at Vanguard as the lead Pre-K and Kindergarten teacher and has over 15 years of experience working with this age group. She has a passion for working with children and strives to provide a safe, loving environment for the children in her class. When Devin is not teaching, she loves spending time with her four children and husband.

Julie Himpelmann

Julie has a Master of Arts in Special Education from the University of Texas of the Permian Basin. After more than four years as a parent volunteer at Vanguard, Julie joined the team in a more permanent role as a lower school Teacher Assistant in 2020. She has a passion for working with Vanguard’s youngest students to help them discover their strengths, grow their confidence, and nurture their independence..

Martha Sharrock

Martha was born and raised in the Dallas area.  She worked in the insurance industry for more than 20 years in the capacity of sales support and then in management.  She also worked in the office for a public elementary school before joining Vanguard in February of 2016 as Registrar/Office Manager.  As she watched students grow, she wanted to work with them more directly, and subsequently obtained her Registered Behavior Technician certification in July of 2019. Martha currently serves as clinical support throughout all grade levels. Martha is married with two sons, one of which is a graduate of Vanguard


Nacima Taibi

Nacima Taibi holds a bachelor’s degree in psychology and the equivalent of a master’s degree in family therapy from the Institute of Family Therapy of Liege, Belgium. She has 13 years of experience working in both school and clinical settings as a behavior therapist. Nacima enjoys spending her free time with her husband and 10 years old daughter. She also speaks four languages!


Tanya Goforth

Tanya has a Bachelor of Science degree in Early Childhood Development, a Master’s degree in Early Childhood Education, and has been in the field of education since 2006. She has experience as a Registered Behavior Technician, is a Reading Intervention Specialist, and has an Elementary Masters of Teaching certification. 

Vanguard Preparatory School

4240 Sigma Road Dallas, TX 75244 | phone: 972.404.1616 | fax: 972.404.1641 | email: [email protected]

Accredited By Southern Association of Colleges and Schools - AdvancED | TEA Approved

Content Copyright 2020 - Vanguard Preparatory School | All Rights Reserved