Gaynor originally worked in the banking industry but retrained as a teacher, becoming a newly qualified teacher (NQT) in 2001. She then became Assistant Head of Year in her second year of teaching and from there progressed to Whole School Literacy Coordinator and then Assistant Head of Faculty for English. Her passion for teaching and learning led her to become an Advanced Skills Teacher in 2007, opening up opportunities to work with colleagues in other schools and allowing her the privilege of working with initial teacher education (ITE) and NQT colleagues.

She took up the position of Deputy Head at Silverdale School in Sheffield, subsequently becoming Director of the Sheffield Teacher Training Alliance (STTA), one of the largest teaching schools in the region, training hundreds of new and existing teachers every year. Whilst at the STTA, she established the National Modern Languages SCITT (the first national SCITT training teachers of modern languages), where she worked with state and independent sector schools to create new partnerships.

In 2019, Gaynor was appointed Principal at Hope Valley College in the Hope Valley, Derbyshire, which received an Ofsted 'Good' rating in October 2023. 

Gaynor's qualifications include:

• Diploma in Banking and Finance (Loughborough University and HSBC)
• BA (Hons) Combined Studies (English and Business)
• PGCE English (Secondary)
• MA Education