Senior Leadership Team (ID 2285)

• Sheba George
  Headteacher
  Sheba George

  Prior to taking up post as Headteacher, Sheba worked as a Deputy Headteacher at Challney High School for Girls, having previously worked as an Assistant Headteacher in Hertfordshire. Sheba has led on Teaching & Learning, Curriculum and Oracy at Challney High School for Girls and in previous roles, has led on Continuous Professional Development, Literacy and worked as a professional tutor for trainee teachers. She has also supported other schools within her role as a Specialist Leader in Education.

• Nic Ponsonby
  Deputy Headteacher
  Nic Ponsonby

  Nic started her teaching career in our school as a newly qualified teacher. She has been in our school for 23 years. Her roles have included many pastoral remits, from an Assistant Head of Year to Head of Year and Assistant Headteacher, Designated Safeguarding Lead and now Deputy Headteacher. Nic teaches Science and is a qualified PE teacher, but has also taught History and Design Technology in her time with us. She was a silver winner in the Pearson Teaching Awards in 2020 for ‘Teacher of the Year'.

• Usman Ali
  Assistant Headteacher (DSL)
  Usman Ali

  Usman joined Challney High School for Girls in September 2022 as a Specialist Leader in Education (SLE) for Computing. Since then, he has taken on the role of Curriculum Leader and joined the Leadership Team as an Associate Assistant Headteacher in September 2024. Prior to this, Usman spent several years working as a Head of Year and House as well as being a Head of Faculty. Outside of the school setting, Usman is a safeguarding governor for a local academy and is a member of the leadership board at an education and youth centre.

  He is now the Designated Safeguarding Lead (DSL), the Senior Mental Health Lead, responsible for community outreach, alternative provisions, pastoral reports and student voice.

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• Lisa Dolan
  Assistant Headteacher
  Lisa Dolan

  Lisa Dolan has been a teacher at Challney High School for Girls for 17 years and has been a teacher for 23 years teaching Physical Education across KS3 and up to KS5, Expressive Arts and Performing Arts at KS4 and Geography at KS3. Lisa has been a Head of Department, Head of Key Stage 4, Head of Year and is now an Assistant Headteacher. Lisa's specialities are in establishing and integrating assessment systems into the curriculum, the analysis of all available data and supporting staff with their own understanding and development of data, to provide the students with the best possible chance of securing the highest outcomes.

• Sam Fisher
  Assistant Headteacher
  Sam Fisher

  Sam joined Challney High School for Girls as the Department Leader of Mathematics in 2019. He started his career at an upper school in Bedfordshire and held various positions throughout his tenure there. As an Assistant Headteacher, Sam thoroughly enjoyed his role in the summer school in the summer of 2021 and is the lead for curriculum planning, including timetabling and, more recently, pupil premium.

• Oliver Smith
  Assistant Headteacher
  Oliver Smith

  Beginning his teaching career in Hertfordshire, Oliver joined Challney High School for Girls as Head of English in 2021, and became an Assistant Headteacher in 2023. He has overseen the Duke of Edinburgh Award in multiple schools in the local area, ensuring students get a chance to push themselves out of their comfort zones and learn valuable life skills. Currently, Oliver leads on Whole School Literacy and Reading within the school; provision for More Able students working alongside NACE, and has worked for Challenge Partners, reviewing practices in other schools.

• Haymie Thaker-London
  Assistant Headteacher
  Haymie Thaker-London

  Haymie Thaker-London joined Challney High School for Girls in September 2025, bringing 20 years of teaching experience in Drama and English. She has previously led Drama as Head of Department and held responsibilities for Pupil Premium, Student Wellbeing, and Literacy. Haymie has recently completed a Master's degree in Educational Leadership, further strengthening her expertise in school improvement and strategic leadership.

  Haymie now focuses on Curriculum Development at Challney High School For Girls, alongside Pupil Premium, Transition, Staff Wellbeing, New Staff Induction, Looked after Children, Post-16 Links, and the Super Curriculum.

• Emma Whitehall
  Assistant Headteacher
  Emma Whitehall

  After starting her career at another local school and holding roles of Deputy Head of House and Health Coordinator Emma joined Challney High School For Girls in 2001 as Head of PE. She is an experienced Assistant Headteacher having specialised in Data and Assessment, Teaching and Learning and Staff Development, as well as being the school's Professional Tutor for a number of years. Emma has a passion for Edtech and led the project when the school was appointed by the DFE as an EdTech demonstrator school, supporting schools nationally throughout the pandemic and beyond. Emma now leads on Technology for Learning as well as the House System and ECT Induction and currently teaches Science at KS3 and 4.

• Jennifer Wright
  Assistant Headteacher
  Jennifer Wright

  Jennifer Wright started her career as a history NQT at Challney High School for Boys, before gaining experience as a Head of history, Head of Humanities, Professional Tutor and a Teaching and Learning SLE. She has worked at Challney High School for Girls since 2017, specialising in Teaching and Learning and the Continual Professional Development of our staff. As part of her CPD role she has led conferences for Women and Middle Leaders, as well as organising a regular programme of weekly CPD for all staff, to ensure an ambitious delivery of the curriculum for our students.