A few days after Debby Lipkin took charge of JFS, she told an assembly of year-11s, "I feel I have come home". It was an "unusual" but "lovely feeling", the turnaround specialist tells me.

The executive headteacher of Europe's largest Jewish school, for the next year at least, was herself a pupil there more than 40 years before, under the tutelage of Dr Edward Conway. "Very happy days," she recalls.

So when, barely a couple of months after arriving as a part-time consultant, she was asked to take the helm following the resignation of headteacher Jonathan Miller in May, she felt the tug of loyalty. "Having been here as a student, how could I walk away?"

Two years ago JFS sailed into choppy waters after the shock of an Ofsted report which downgraded it from outstanding to a school requiring improvement. While some felt the school may have been hard done by, she diplomatically refrains from passing comment. "It's difficult to say because I wasn't here," she says.

However, there is no mistaking her resolve that she is there to oversee "rapid and robust improvement" - an interesting choice of words, and of course, just what the Ofsted report said was needed.

The inspectors had been due back last term, but the school gained more breathing space after Ofsted extended the period for follow-up visits to 30 months. "I think Ofsted has recognised that sometimes two years are not enough," she says. "If you can imagine a very big tanker and lots of things to do to make it really seaworthy, to turn it around is a very big job."

Before JFS, she had been parachuted into a similar role at Nightingale, a multi-faith, multi-ethic academy in north London. Before that came one of her most challenging assignments, to help a secondary special-needs school for boys. She remains a consultant to a Catholic school in north-east England.

While each school had its own needs, the degree of change required at JFS is no greater. "It's just a different setting. Improving a school is the same everywhere, whether I am in Buckinghamshire, Billingham or Berkshire. The cultural or ethnic make-up may be different, but at the end of the day we all want the same - the best education we can give to our children."

Professionally, she started in the Jewish system. After taking a history and education degree, she taught for three years at the Brodetsky Jewish Primary in Leeds, where her husband David was studying medicine. When they moved back to London, she went to a succession of Orthodox primaries, North-West London Jewish Day School, Menorah, Beis Yaakov and Sinai.

At Sinai she was responsible for inclusion, encompassing any child requiring additional attention. Later, she led a Department for Education project to "support the most vulnerable children in our society". She streses that she is "a great believer in educational opportunities for all children".

In 1993 she joined the school improvement team for Brent, which happens to be the local authority for JFS. When she became an independent consultant in 2000 to stretch her wings, she retained links with them.

It was through Brent that she came to JFS. As Ofsted demands had changed in recent years, her council brief was to "coach and mentor" local schools on Ofsted's expectations. With a follow-up inspection due, she was part of a Brent team invited by the school to help JFS prepare for it. "As a result of that, Mr Miller and Brent agreed that I would be on loan for two days a week."

So she was "very much" surprised to be catapulted soon after into the head's office. It was "circumstance, I suppose. If somebody else had been here, perhaps it would have been that person."

Prior to Mr Miller, JFS had been used to strong female leadership in the form of Jo Wagerman and Dame Ruth Robins. Mrs Lipkin exudes a quiet assurance, controlled and precise rather than demonstrative.

Despite JFS's strong exam record, Ofsted found that not all students showed a "positive attitude" to learning, disciplinary sanctions were inconsistent and monitoring of behaviour ineffective.

While change was under way when she took up her post, she says, "we are building on those improvements by making sure we have the right people with the right skills and experience."

She has refreshed her leadership team, recruiting an "outstanding" maths teacher to supervise "data and progress", so that the school can keep track of attendance and pupils' progress. She has appointed an assistant head for "inclusive practice" to support children with various needs, including "higher attainers to make sure they achieve to the best of their ability".

One significant change has been to the early years accelerated stream.

Until now, the majority of the most able 40 per cent of pupils have been banded into groups and taught together for most subjects in the first two years.

"It didn't allow for those children who were very good at maths, for example, but not so good at English," she says.

Children will now be taught in sets in their early years, creating a more "fluid system which will allow children who are good at one subject but need more support in another to be correctly placed. And also to create slightly smaller groups for those children with barriers to learning who may require additional support."

It is a change which reflects the recent work done to clarify the school's vision. The Hebrew motto on its badge, "light and honour" (from the Book of Esther), has been translated to signal its mission for every child "to be enlightened and to be valued".

"Maybe previously if you weren't in the accelerated stream, you might not have felt as valued," she says.

One of the four deputy heads, Simon Appleman, is assisting as acting headteacher, but two of the other four deputy posts remain to be filled, including the one responsible for Jewish life.

While JFS will remain "an inclusive, modern, Orthodox school" under the umbrella of the United Synagogue, she expects "profound change" to result from a review of its Jewish studies.

Every child should leave feeling comfortable with their Judaism so that "if you go into shul you can pick up a siddur and daven if you need to; if unfortunately, you lose a parent, you can say Kaddish; if you need to say kiddush on Friday night, you know how. If you want to go to Israel, you have a strong identity with Israel. If you want to be a cultural Jew, you are very aware of your history."

The curriculum was not always delivering that. "We want to provide a range of pathways for our students because they are so broad church. If someone comes in not reading Hebrew, which happens, we want to make sure we can offer a programme where they learn to read."

She adds that there is also going to be a "timetable review to see if we can create more time for English, maths and JS (Jewish studies)".

Although the chairman of the governors, Steven Woolf, stepped down after little more than a year because of time constraints, former chairman of governors Arnold Wagner is now "providing stability" until a new chairman is elected in September.

Of her own position, she will say no more than that it is scheduled to last a year, but that she hopes she can continue to do "a range of consultancy work".

She expects to introduce more "open door" polices during the year . "My door is always open, for parents, students and staff. In fact, we had a meeting with prospective parents in someone's home - a very informal, open, welcoming, warm approach."

But she is not so relaxed as to allow the return of muck-up day, after the adverse publicity that followed the antics of some year-11s last summer. This year's year-11 send off, she says, was "wonderful - the children had a fabulous time, parents were here, it was enjoyed by all. That's how it will be."