Ms Simpson, 23, already teaches GCSE physics at Verulam boys' comprehensive in St Albans, Hertfordshire, and runs the school's Year 7 Space Club, building model rockets.
But her biology degree limits her to teaching only that subject at A-level - despite the shortage of physics and chemistry staff.
The Training and Development Agency for Schools is inviting tenders this month for a pilot scheme to retrain up to 150 teachers in physics and chemistry, and this week the Government agreed to offer cash incentives to entice teachers. The School Teachers' Review Body report has presented new evidence of the looming shortage of quality physics, chemistry and maths teachers, and said schools should be willing to pay more to fill the gaps.
Ms Simpson said she would love to have an extra pound;5,000 to retrain, especially on top of the pound;5,000 golden hello she is paid as a new science teacher.
She welcomed the prospect of climbing the pay scales judged on her performance, as long as she was not assessed purely on the raw test results of struggling students.
"I'm already doing an awful lot around the school in terms of extra-curricular activities that are unpaid," she said.
Last year, research showed that teachers starting their careers were more likely to get good results than more experienced colleagues.
Ms Simpson acknowledged that automatic pay progression had its merits in recognising long service.
"But the downside is that some teachers may get complacent, when they're going to get a pay rise whether they work hard or not," she said. It was time, she said, for a change.