CHIEF EXECUTIVE OFFICER

 Tanner Sierks is the CEO and Owner of Willow ABA Services and The Willow Academy. With over a decade of experience in the field, Tanner’s mission has always been to provide high-quality ABA services and ensure that all families, especially those facing barriers to care, can access exceptional support. Under his leadership, Willow ABA has grown into a multi-state organization offering in-home, clinic-based, and school-based services. Tanner remains grounded in the belief that meaningful progress happens when families and clinicians work together with compassion and shared purpose. In his free time, he enjoys visiting the beach with his wife, Malorie, and their four children along the beautiful North Carolina coast.

CHIEF CLINICAL OFFICER

Dr. Ariella Parker is a Board Certified Behavior Analyst who holds a Ph.D. in Education with an emphasis in Special Education, Disabilities, and Risk Studies from the University of California, Santa Barbara. With more than 20 years of experience, she specializes in supporting early language acquisition and increasing social communication skills and engagement in young autistic children. Ariella is committed to evidence-based, compassionate, and neurodiversity-affirming practices and to building strong, supportive clinical teams. She finds deep joy in helping children connect, communicate, and thrive. Outside of work, Ariella enjoys hiking, music, and spending time with her husband, three sons, and their Golden Retriever.

CHIEF FINANCIAL OFFICER

 Tom Forde is a seasoned finance and accounting executive with over two decades of experience guiding startups, established platforms, and multinational enterprises. As Chief Financial Officer of Willow ABA, Tom has helped shape the company into a financially strong, multi-state organization recognized for operational excellence. Having worked alongside ABA leaders for over a decade, Tom believes that financial systems should always support purpose, and that purpose is helping children and families thrive. He is proud to use his expertise to empower teams who change lives every day.

CHIEF OPERATING OFFICER

Sierra earned her Master’s in Business Administration in 2017 and has been with Willow since its founding in 2020 as one of the original team members. She entered the field of Applied Behavior Analysis (ABA) in 2019 and quickly fell in love with the families she serves. Sierra is passionate about ensuring that Willow’s operations always reflect and support its mission to provide high-quality, compassionate ABA services to every child, no matter the obstacles they face. She is deeply proud to help create a company that makes a meaningful difference in the autism community. In her free time, Sierra enjoys camping with her husband and children and exploring all that Colorado has to offer.

CHIEF CLINICAL QUALITY OFFICER

Elle earned her Master’s degree from The Ohio State University and became a Board Certified Behavior Analyst (BCBA) in 2017. As one of Willow’s founding clinicians, Elle has been part of the organization since its beginning in 2020. Her vision has always been to help create a company built on exceptional clinical quality and genuine connection, where every child receives truly individualized care, and every family and team member feels seen, supported, and valued. Elle believes deeply in compassion-driven progress and in the power of community within the autism field. Outside of work, she enjoys spending time outdoors under the Colorado sun with her husband and daughter.

REGIONAL CLINICAL DIRECTOR

Kayla began her ABA career as a Registered Behavior Technician (RBT) and advanced through roles as Lead RBT, Board Certified Behavior Analyst (BCBA), and Clinical Supervisor before becoming Clinical Director when Willow opened its first Kansas location in 2020. She now serves as Willow’s Regional Clinical Director, guiding both clinical and operational services across all sites. Kayla believes deeply in individualized, compassionate, and trauma-informed care and works closely with Clinical Directors to ensure every family receives services rooted in respect and understanding. Her greatest joy comes from seeing meaningful progress in the children and families that Willow supports.

DIRECTOR OF RCM

Ivanna has been part of the Willow team since 2023 and began her ABA journey in 2019 as a Registered Behavior Technician. She now serves as Willow’s Director of Revenue Cycle Management, where she helps families navigate the insurance process so they can more easily access care. Ivanna is passionate about ensuring that every family receives the support they need without unnecessary barriers. She is proud to be part of a company that puts children and families first. In her free time, she enjoys relaxing with her husband and their bearded dragon at their home in Houston, Texas.

DIRECTOR OF TALENT ACQUISITION

 Gillian has worked in the field of ABA since 2013 and joined Willow in 2022. After years in both clinical and leadership roles, she found her passion in bridging the gap between clinical and administrative teams to help create a more compassionate and inclusive field. As Willow’s Director of Talent Acquisition, Gillian loves connecting with people who will nurture the relationships and culture that allow both clients and staff to thrive. She believes that the right team can change lives, and that kindness and collaboration are at the heart of meaningful care. In her free time, Gillian enjoys creating music, exploring the outdoors, and spending time with her husband and their rescue pup, Mipha.

FAMILY INTAKE COORDINATOR

Yuliana earned her bachelor’s degree in Interdisciplinary Psychology in 2023 and began her career in ABA supporting families in crisis. She later transitioned into a dual role as an RBT and administrative team member, where she discovered her passion for connecting families, especially Spanish-speaking families, with the support and information they need. She joined Willow in 2024, continuing her mission to ensure that every family feels informed, supported, and hopeful throughout their ABA journey. Yuliana is proud to help create an inclusive, welcoming experience for all who walk through Willow’s doors. Outside of work, she enjoys exploring new restaurants with her husband and son.

FAMILY INTAKE COORDINATOR

Michelle earned her bachelor’s degree in Psychology from the University of California, Berkeley in 2022. She first discovered her passion for Applied Behavior Analysis during her undergraduate studies and began her career as a Behavior Technician after graduating. While she loved supporting clients directly, she soon discovered a deeper passion for working behind the scenes to help families navigate the process of accessing essential services. Michelle honed her skills as an Intake Receptionist before joining the Willow team as an Intake Coordinator. Her favorite part of her role is guiding families through the intake process, ensuring it is as smooth and stress-free as possible. She is dedicated to making every family feel supported and informed from their very first point of contact. Outside of work, she enjoys exploring all that California has to offer with her family and friends.

LITTLETON CLINICAL DIRECTOR

Dr. Valeria Armendariz joined Willow ABA in 2022 as the Clinical Director of the Littleton, Colorado clinic. She recently earned her Ph.D. in Applied Behavior Analysis, focusing her dissertation on promoting self-advocacy in children with autism by teaching and honoring assertive communication across social settings. Valeria is passionate about tailoring ABA strategies to meet each client’s unique strengths and helping families thrive together. She is proud to be part of a team that celebrates neurodiversity and leads with compassion. Outside of work, she enjoys exploring Colorado with her husband and their dog and visiting family in Tucson, Arizona.

LITTLETON OPERATIONS MANAGER

Anna began working with neurodivergent communities in 2016, primarily through summer camp programs. After earning her Master’s degree in Psychology and relocating to Colorado, she held several management roles and discovered her passion for bringing people together to achieve shared goals. Anna joined Willow in 2023 and feels grateful to contribute to an organization that values teamwork, kindness, and high-quality care for the autism community. Outside of work, she enjoys outdoor adventures and cooking creative meals with friends.

LENEXA CLINICAL DIRECTOR

 Abigail (“Abby”) earned her undergraduate degree in Applied Behavior Analysis from the University of Kansas in 2013 and her master’s degree in Applied Behavior Analysis from Arizona State University in 2019. She joined Willow in 2022, first as a BCBA before moving into the Clinical Director role. Abby was inspired to join the field of ABA after working with a family whose child was diagnosed with autism, and she has been passionate about supporting communication and family growth ever since. She feels honored to be part of a company that celebrates every child’s unique strengths. In her free time, Abby enjoys spending time with her growing family, doing puzzles, and exploring new restaurants.

REGIONAL OPERATIONS MANAGER

 Nina began her professional journey as a sea lion trainer, where she was first introduced to the science of behavior. She fell in love with ABA and transitioned to working with children as an RBT before becoming Operations Manager at Willow’s Lenexa Clinic. Since then, she has supported the growth of many Willow clinics and now serves as Regional Operations Manager, helping ensure that each location runs smoothly and delivers exceptional care. Nina is proud to work for a company that prioritizes families and strives to make high-quality ABA accessible to all. In her free time, she enjoys being outdoors with her dog and reading.

WILMINGTON CLINICAL DIRECTOR

Katie began her career in ABA as an RBT while earning her undergraduate degree in Special Education with a minor in Psychology from Campbell University. She later completed her Master of Arts in Psychology with a concentration in Applied Behavior Analysis from the University of North Carolina Wilmington. Katie has supported children, teens, and adults with autism and developmental disabilities across home, community, residential, and clinical settings. She joined Willow ABA in 2023 to help establish the Wilmington location, where she now serves as Clinical Director. Katie is passionate about ensuring that every client receives compassionate, neurodiversity-affirming, and socially meaningful care.

LAWRENCE CLINICAL DIRECTOR

Robin earned her B.A. in Applied Behavioral Science from the University of Kansas and her M.Ed. in Education from Lesley University. She is currently pursuing a doctoral degree in Interdisciplinary Leadership from Creighton University. Robin has worked in the ABA field since 2011, both in the U.S. and the UAE, and joined Willow in 2023. Her passion for helping children communicate and advocate for themselves drives her work in providing in-home ABA services for families in and around Lawrence, Kansas. Robin is proud to be part of a company that values empathy, equity, and family connection. In her free time, she enjoys spending time with her husband and daughters and building intricate Lego sets.