To make matters worse, she has no idea if she will be working after the summer holidays as her temporary contract ends next month.
But some of the gloom has now been lifted by the Teachers' Benevolent Fund, which has agreed to clear her Pounds 350 overdraft, give Pounds 100 for clothing for each of the children and provide a Pounds 5-a-week top-up to the family's Income Support payments (a niggardly amount, the fund's administrators agree, but the maximum that Department of Social Security regulations allow them to give without inviting a penalty).
Jane is only one of 1,200 people who have received grants totalling Pounds 273,610 from the fund in the past year. The fund was set up by the National Union of Teachers' predecessor, the National Union of Elementary Teachers, in 1877, but it helps teachers in any union - or none - as well as their dependants.
It also assists teachers in the private sector and lecturers in both further and higher education. Many of the grants, which can amount to as much as Pounds 1,500, are made to eradicate debts or help the applicant to make ends meet, but others are for specific items such as a cooker or a rare holiday.
One grant recently allowed the family of a mentally and physically handicapped six-year-old to buy a computer touchscreen which has enabled him to learn several words. At the other end of the age scale, an 88-year-old retired teacher has received a Pounds 20-a-week grant towards the cost of her residential home place.
Most of those applying for assistance, however, are younger teachers. Many are single parents, but some have partners who have gone bankrupt. In the past few years there has been a marked, and worrying, increase in the number of newly-qualified teachers seeking help - one young single mother recently contacted the fund in desperation after accumulating debts of Pounds 5, 000 during her teacher-training course.
Another sign of the times is the large number of teachers who retire prematurely because of a stress-related health problem, and then discover that their pensions cannot cover their outgoings. Bob Cherry, the TBF's treasurer, said: "We find that such people often can't make ends meet because they have a mortgage and perhaps have children at university. Many people in this age group also have to support elderly parents."
Owing to these new pressures - and the fact that there are more retired teachers because people are living longer - the TBF's 38-member council found itself handing out 16 per cent more in hardship grants last year than in 1993. But it still had to turn down some appeals for help or give less than was requested.
Sometimes the "We regret to inform you . . ." letter is sent out because inquiries reveal that the applicant still has some money in the building society. "Some put money away for a rainy day and then don't seem to realise that the rainy day has arrived," said Mr Cherry, a retired teacher from Stoke-on-Trent.
But that is a relatively rare occurrence. The main reason that applicants are disappointed is that the demands on the fund have outstripped its income. Because most of its support has traditionally come from the National Union of Teachers - the TBF offices are still in the basement of the union's King's Cross headquarters - the fund has felt the pinch as the union's membership has declined. Legislation forbidding employers from deducting union dues from salaries was another body blow, as some of the NUT subscription automatically went to the fund.
For a time, the TBF survived by drawing on its reserves and even selling some of its seed corn - income-bearing investments. Two years ago, the fund's prognosis was so bad that even its supporters were predicting it could continue for no more than another three or four years. But it has edged away from that precipice by establishing a fund-raising department and a computerised database of the 13,000 teachers who make regular contributions. As a result, the TBF supporters have received more direct mailings appealing for help, and have responded generously.
"At one time the average contribution to the fund was Pounds 12 a year but it is now more than Pounds 30," said Viraj Jethwa, the fund's managing secretary. "We realise, however, that we need to attract more supporters, particularly among the younger age groups. We have been in contact with other unions such as the National Association of Schoolmasters Union of Women Teachers and are hoping that they will allow us access to their membership, too.
"We have a close involvement with NATFHE, the lecturers' union, which has two members on our council, and the Professional Association of Teachers makes an annual donation."
A continuing problem that the TBF still has to resolve, however, is under-occupancy in its four residential homes for retired teachers, a situation that may improve after a planned refurbishment scheme.
There is also the more intractable problem of low interest rates and the poor performance of the UK stock market depressing the rate of return on the fund's investments.
But it appears that the TBF can at least count on one substantial source of income - legacies. Last year, it received nearly Pounds 300,000 in bequests and 80 per cent of the cash came from kind-hearted spinsters. Contrary to popular belief they do not leave all their money to cats' and dogs' homes.
TBF, Hamilton House, Mabledon Place, London WC1H 9BE (tel. 0171-465 0499).
Additional research: Maureen McTaggart