A. Hallfrisch - Head of School

April Hallfrisch

Head of School

April Hallfrisch started with BASIS when it opened one of its first primary campuses in San Antonio in 2017 as a 4th grade Humanities teacher before beginning her role as a Director of Student Affairs in 2018.  She went on to the role of Director of Academic Programs in 2019 and recently became the Head of School here at BASIS San Antonio Primary-Medical Center Campus.

April began her career in education in Minnesota and relocated to Texas in 2006.  With over 16 years of experience as an educator, she has worked diligently to establish a rigorous program and build a strong rapport with her students.  Additionally, over the span of her educational career, April served as a middle and high school English teacher, English department chair, and was Teacher of the Year in 2017.

April holds a Bachelor of Arts in English and is a Texas certified teacher.

As the Head of School, April believes that education creates an opportunity for all students to grow regardless of ability and background, and embraces the BASIS model of facilitating student growth through high expectations and academic support.  Go Badgers!

Contact April Hallfrisch

Amanda Martinez-Walthall

Amanda Martinez-Walthall

Head of Operations

Amanda Martinez-Walthall began her BASIS Charters Schools career at BASIS San Antonio – Shavano in the summer of 2017 as the Curriculum Coordinator. Two years later, she moved into the role of Director of Academic Programs. The 2021-22 school year has brought her to BASIS San Antonio Primary – Medical Center as the Head of Operations.

Mrs. Walthall earned a BBA from St. Mary’s University where she majored in Marketing and Business Administration. Prior to joining the BASIS community, Amanda managed a cheerleading facility where she created a curriculum for all-star competitive cheerleaders as well as developed a leadership program for young athletes. Amanda also worked for the National Cheerleaders Association where she mentored and trained collegiate cheerleaders, high school and college level cheerleading coaches, and high school cheerleaders around the state of Texas.

Contact Amanda

Ashley Trevino

Ashley Trevino

Director of Student Affairs

Ashley Trevino joined BASIS San Antonio Primary Medical Center Campus in 2017 as a Second Grade Learning Expert Teacher during the first year as a primary campus. Though her years in this role, it prepared her to take on the role as a Dean of Students in 2020 in supporting our campus and students in academics and behaviors. She recently became the Director of Student Affairs after realizing that her passion lies in student development socially, emotionally, behaviorally, and academically.

Ashley earned her Bachelor’s Degree in Communication Disorders with a minor in Psychology from Our Lady of the Lake University in San Antonio, Texas. Before joining BASIS San Antonio Primary Medical Campus, Ashley worked as a speech therapist assistant for home health agencies in San Antonio and surrounding areas. Her passion working with children helped her quickly realize that education is where her heart lies.

Ashley seeks to bring her passionate commitment to education and her vision for leadership to the field of education. She is committed in collaborating with students as they develop their ability to become critical thinkers, problem-solvers, innovators, effective communicator’s, and self-directed learners.

Contact Ashley Trevino

Joylynn Nesbitt

JoyLynn Nesbitt

Director of Academic Programs

JoyLynn Nesbitt joined BASIS Charter Schools in 2019 as the ESL Coordinator at BASIS San Antonio Primary Medical Center. She has been working in the education field since 2006 after she received her Bachelor’s degree from Baptist Bible College. Mrs. Nesbitt has taught all grade levels, both in the United States and in Thailand. As she continued to work in education, she received her Master’s in Teaching English as a Second Language from the University of Texas at San Antonio in 2012, along with her Texas teacher certification.

Prior to joining BASIS Charter Schools, Mrs. Nesbitt worked in the ESL department for another San Antonio-based charter school. In addition, she taught in one of the largest public school districts in San Antonio, leading ESL programs and professional development. Mrs. Nesbitt has spoken at state conferences on ESL topics, specializing in refugees and delayed language development. She accompanied these conferences with her published book “A Cross-Curricular Guide to Teaching Beginner ELLs and Refugees.

Mrs. Nesbitt is excited to serve the BASIS San Antonio Primary Medical Center community as the Director of Academic Programs. She believes that every educator has the ability to consistently grow to better guide their students and parents toward success.

Contact JoyLynn Nesbitt

Isabel Villarreal

Director of Operations

Isabel Villarreal joined BASIS Charter Schools in 2020 as a third grade Learning Expert Teacher before beginning her role as the Reading Specialist in 2021 and most recently the Director of Operations here at BASIS San Antonio Primary-Medical Center Campus.

Isabel has 20+ years of experience in the education field. In 2012 she received her bachelor’s degree with emphasis in Early Childhood from Texas A&M University-San Antonio followed by her master’s in Reading Specialization in 2015.

Prior to joining BASIS Charter Schools, Isabel taught in many capacities from preschool through third grade. In 2016, while teaching full-time, she started a reading intervention program which she lead for four years. This included teacher training, testing, progress monitoring and administration of testing measures. Isabel also spearheaded a benchmark testing program that was later implemented as a pilot program for the district.