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About Us


Meet the Team at Texas Center for Educational Testing, LLC.

Stacey Cox M.Ed., CALT

TEA Certified Educational Diagnostician I Lead Diagnostician
ICD Level II ADHD Specialist

Stacey Cox earned a bachelor’s degree in early childhood through 4th-grade education from Texas Woman’s University and holds a master’s degree in special education from the University of Texas at Tyler.

Stacey worked for Denton Independent School District from 2004 to 2017. During the first five years of her career, she taught 1st grade, 2nd grade, and English as a second language. After her classroom experience, she completed a two-year dyslexia training program at the Texas Scottish Rite Hospital for Children, obtaining her licenses as a Certified Academic Language Therapist and Dyslexia Therapist. For the next eight years, she served students with dyslexia in Denton ISD.

In 2017, after earning her certification as an educational diagnostician, Stacey began contracting with several private practices in the metroplex and working with the Denton ISD dyslexia department, as well as other local school districts.

In 2020, Stacey opened the Texas Center for Educational Testing, providing comprehensive assessments for children and adults of all ages. She also began contracting with the Denton County Special Education Cooperative, assessing students in Sanger, Aubrey, Krum, Ponder, and Pilot Point ISDs. In December 2024, she relocated the testing center to Flower Mound, Texas.

With over 21 years of experience providing intervention programs and assessments for students with learning disabilities in both public, private, and charter schools, Stacey has extensive knowledge of research-based evaluation tools and identification criteria for ADHD and learning disabilities, including dyslexia, dyscalculia, and dysgraphia.

She is trained in and has implemented Orton Gillingham-based programs, including Take Flight, Pre-Flight, Rite Flight, MTA, and Alphabetic Phonics. Her expertise allows her to recommend specialized instructional plans and appropriate accommodations to maximize learning potential for individuals in both classroom and work settings.

Stacey holds state certifications in:

  • General Education (Early Childhood-8th grade)
  • English as a Second Language
  • Educational Diagnostician
  • Certified Academic Language Therapist (CALT)

Kimberley Henning, M. Ed.

TEA Certified Educational Diagnostician

Kim Henning graduated 1980 from Texas Woman’s University with a Bachelor of Science in Education, certified in Elementary Education (K-8) and Generic Special Education.

In 2001, she obtained a Master’s in Special Education and an Educational Diagnostician certification from the University of North Texas.

This marks Kim’s 36th year in education. She taught for 15 years in the classroom, covering all levels of special education and spending 2 years as a First Grade Teacher.

Kim has spent 21 years (and counting) as an Educational Diagnostician, specializing in high-quality, individualized assessments to determine student’s strengths and weaknesses and help them succeed. Kim is knowledgeable about public school systems, expectations, and curriculum standards.

In addition to her professional work, she is the mother of two, grandmother to three teens and preteens, and a proud dog mom.

Rahna S. Cutting, M.A, LCDC, LPC-S

Litigation Consultant

Rahna Cutting has collaborated with the diagnosticians at The Texas Center for Educational Testing since its opening in 2020. She offers psychological consultation services that include endorsing DSM coding and reviewing reports to diagnose mental disorders such as ADHD in both children and adults.

Before transitioning to a career in educational counseling, Rahna was a certified teacher. She worked with Texas students of all ages, from kindergarten through college, teaching language arts and physical education, and a course in the family sciences/counseling department at the University of North Texas.

With over 30 years of experience as a private practice clinician and 15 years of trial experience as a litigation consultant, Rahna has navigated court-related processes and participated in over 500 court-appointed evaluations. She has served as an expert witness more than 50 times, making her an invaluable asset for anyone involved in litigation matters concerning children.

Rahna has been married for 25 years and has eight grandchildren.

Shellie Lackey, LDT, CALT

Director of Client Services

Shellie Lackey is the Director of Client Services at the Texas Center for Educational Testing. She earned her bachelor’s degree in education with a minor in reading from Texas Woman’s University, specializing in teaching kindergarten through eighth grade. Shellie completed a two-year dyslexia training program at the LEAD Training Center, where she received licenses as a Certified Academic Language Therapist and a Licensed Dyslexia Therapist. Additionally, she holds certificates in Special Education and English as a Second Language (ESL).

With 25 years of experience in the classroom, including 15 years as a licensed dyslexia therapist and Certified Academic Language Therapist, Shellie has worked in several school districts, including Valley View ISD, Krum ISD, Denton ISD, and Key School in Fort Worth. She currently serves as the reading interventionist at Selwyn Elementary in Argyle.

When Shellie isn’t working, she enjoys spending time by the pool with her family. Family is everything to her, and she adores her three wonderful grandchildren. She and her husband love exploring new restaurants, attending concerts, and watching movies together. Additionally, Shellie likes listening to audiobooks while unwinding with casual games.