It was an unusual approach, but it worked. The man, Bob Kaye, was the head of PE at Ormesby secondary in Middlesbrough, and Ms Thompson soon found herself working as an instructor, teaching English there full-time. She was 21, had no formal training and was teaching Years 7, 8 and 9 for 25 hours a week on a salary of just pound;15,500.
Ms Thompson fell into supply teaching when trying to scrape together the money to train as a journalist after completing an English degree.
"A friend said I could get work if I had a degree in a national curriculum subject. I went to five or six different schools in about a month, but to be honest I felt like a fraud."
She went to an interview for the teaching job, but she said: "It was assumed by the head that I had the job." The school did not even ask for her CV.
She jumped at the chance of regular work, and started in January. She told the school that she would be leaving in September, which she did.
With so little experience, she found the first few weeks difficult. "The head of English was helpful, but there was an Ofsted inspection in my third week. The other teachers gave me lessons plans for that, but otherwise it was up to me to devise lessons," she said.
"My pupils' English books weren't checked. I often felt that I could have been doing what I wanted and no one would have known. If I had been doing it as a career, maybe I would have had a support network, or if I had talked more to my head of English.
"It was bloody hard, to be honest. At parents' evenings I would think, 'How am I authorised to give these people my view on their children when I am not actually a teacher?' I would look at the dinner ladies and cleaners and think, 'I would rather have your job'."
Colin Algie, her headteacher, said: "I would choose a qualified teacher every time, but one of our qualified teachers decided to join a mentoring scheme and Ms Thompson was hired for the interim period."
Recruitment has been a problem for the school, which has advertised the post of head of PE three times without results.
The Department for Education and Skills allows unqualified teachers to work in schools if they have a specialist qualification or experience. They should be employed only if the school cannot find a suitable qualified teacher.
Fiona Eldridge, who is chair of the supply teaching agency Teaching Personnel (not the agency Ms Thompson worked for), said: "There are a lot of unqualified teachers who are really excellent and doing a great job. We always make sure the school is aware of the situation, and we prioritise fully-qualified teachers."