Principal's Welcome

  • me

    My name is Diona Brown, and I am very excited to serve as your new MMS principal, beginning this summer. Currently, I am the principal of Park Street Elementary School, a position I have held since 2018. The opportunity to lead Marietta Middle School is both an honor and a blessing, and I look forward to partnering with each of you.

    Rather than share my background, I want to focus on what matters the most: your student and their experience at MMS. My two immediate priorities for MMS will be addressing and enhancing academic rigor (both within the new Advanced Studies program and throughout the school) and focusing on student safety and well-being. One of my favorite leadership quotes is from Lisa Haisha: "Great leaders don't set out to be a leader, they set out to make a difference. It's never about the role, always about the goal." At MMS, one of my top goals is to partner with you to enhance your student’s experience in and out of the classroom.

    My passion for education began as a child watching my mother and grandmother teach and impact students' lives. As 2014-2015 Teacher of the Year at Northwestern Middle School in Fulton County, I know what it means to strive for excellence and to do the hard work needed for positive results. During my years at Park Street, we increased student achievement and enjoyed immense academic success and growth. Based on the 2020-2021 MAP results, we were the only elementary school to grow in every grade and content area (grades 2-5) from Fall to Spring. We also created exciting opportunities for our students, including summer learning internships for our 5th graders and a Dual Language Immersion program that will start in the fall. Further, I was involved in designing and opening the new Park Street school building.

    I have high expectations and aspirations for MMS, and I thank you for entrusting your child's middle school education and enrichment to the team of administrators and educators at Marietta Middle School.


    Your New MMS Principal,

    Diona Brown, Ed.S.


Administration Team Contacts



    Mr. Anthony Booker

    7th Grade Administrator

    My name is Anthony Booker, and I am the 7th Grade Assistant Principal at Marietta Middle School. I am married with two children, and I have lived in Cobb County for more than 30 years. I earned my first degree from Georgia Tech, and my three education degrees are from Kennesaw State University. I have worked at Marietta Middle School since 2008 as a teacher, academic coach, and assistant principal. I have received an Outstanding Employee Award from Marietta City Schools, and I have awards from the Marietta Business Association, Kiwanis, and Kennesaw State University. My wife and I are foster parents, and we care deeply about helping the most vulnerable children in our community.


    Ms. Lisa Cox

    Teacher Support Specialist- Special Education



    Mrs. Celis Hartley Lewis

    8th Grade Administrator

    Celis Hartley-Lewis has 22yrs of secondary science teaching experience ranging from 7th to 12th grade. She previously served as district Science Coordinator as well as the Assistant Principal at Burruss elementary.  She holds a Bachelor’s degree in Biology, a Master’s Degree in Curriculum Instruction and Assessment, as well as a Specialist Degree in Education Leadership. She has been married to Stan Lewis for 27yrs and has two sons Alex (MHS class of 2015) and Andrew (MHS class of 2025). Celis brings her vast K-12 experience to help our MMS students successfully transition to the high school.


    Ms. Mary Thurman
    Scheduling Administrator  

    Mary Thurman has been a middle school educator for 22 years.  She began her career as a middle school mathematics teacher, teaching classes from 7th Grade Math to Honors Geometry at the eighth grade level.  During this time she served in several school-level leadership positions as well as district committees which supported the rollout and curriculum development for the Georgia Performance Standards of Mathematics.  In addition, she served on the Teacher Advisory Council for State Superintendent Kathy Cox.  In 2008, Ms. Thurman was recognized as Marietta Middle School’s Teacher of the Year! She transitioned into the role of School Improvement Specialist and IB MYP Coordinator in 2014 before becoming Assistant Principal at MMS in 2016.  Ms. Thurman holds a Bachelor’s degree in Mathematics from University of Tennessee, a Master’s Degree in Secondary Instruction from University of Tennessee, and a Specialist Degree in Educational Leadership from Kennesaw State University.


    Ms. Heather Welch
    School Improvement Specialist

    Ms. Welch has been an educator for 25 years. She served as a Classroom Teacher in East Cobb, Marietta, and Roswell prior to being promoted to Curriculum Support Teacher Specialist in Alpharetta. She is a two-time teacher of the year and believes in reflection, data and continuous growth. She also has experience creating and facilitating professional development at the school & district level. Ms. Welch has delivered adult professional development in all subject areas as well as technology integration, Science of Reading and instructional strategies. 

    Ms. Welch received her Bachelor’s Degree in Elementary Education (PK-5) and a Master’s Degree in Educational Leadership and Administration (K-12) from Kennesaw State University. Ms. Welch is also a lifetime certified Teacher Support Specialist. Ms. Welch has an adult son, Nick, and a Shih Tzu puppy named Clover that she loves to play with and spoil. Ms. Welch was influenced and mentored at a young age by many educators, but especially her mother, who served as an educator and administrator in multiple public and private schools and districts.