She is one of the teachers, nurses and police officers trapped by the downturn in the residential property market - a downturn that has coincided with the Government's clampdown on teachers' pay.
The scheme allows workers to buy a share in their rented property or in a newly-built home. Alternatively, they can get a loan of up to pound;50,000, or pound;100,000 for certain London teachers, to help them buy a home on the open market.
Ms Connaughton, 36, fitted the typical demographic for the scheme, as she was a single, female teacher who had moved to London to fill job shortages.
She saw a brochure for the scheme in 2005 while working as a teacher at Ursuline High School in Wimbledon. That August, she moved into a new first-floor apartment near Kingston upon Thames station. The purchase price was pound;199,995; she paid pound;63,000 and Broomleigh Housing Association bought the other pound;117,000 share.
On her teaching salary, she was able to cover her mortgage and the rent to Broomleigh, and plan to eventually buy out the housing association.
This year, however, for family and work reasons, she returned home to Manchester. But she found she could only sell her share of the apartment to another key worker. Several months on, she has had no success.
She is not allowed to let out the property, so is left paying pound;800 a month in mortgage and rent on an apartment that sits empty.
She has meanwhile found a good new job as head of humanities at Sale Grammar School in Cheshire, with an annual salary of pound;42,000.
"I should be excited about my new job but I'm just worried about money all the time," she said. She lives with her new boyfriend, who is subsidising her living costs: "I'm pretty good with money, and I've never been much in debt before."
Howard Catton, head of policy for the Royal College of Nursing, said the downturn in the property market would leave other key workers trapped.
The Housing Corporation receives almost pound;1 billion to support shared ownership schemes. It put 7,400 key workers into homes last year and expects to house another 13,000 by the end of this year. Education workers make up almost half the buyers.
A Government analysis of the scheme last year said the state of the housing market would help determine whether it offered workers value for money, long term.
Nick Dudman, Broomleigh's interim chief executive, called for the Government to make it easier for key workers to exit the scheme.