When JFS students returned after half-term this week, new headteacher Rachel Fink was waiting for them.

The former head of the girls’ division of Hasmonean High School says she chose to start now rather than wait till the new academic year in order to have half a term to familiarise herself with her new school. “I am not the person who walks in to make change for change’s sake,” she says. “I want to hear what people have to say and see for myself how things are.”

Her bright personality is matched by the colour of the scarves that wreathe her head. But she is aware of some bemused parents wondering if the appointment of a hair-covering teacher from Hasmonean signalled a plan to shift JFS religiously to the right.

“People see a head covering and they think the mad frummer has come to town,” she laughs. “That’s absolutely not who I am.” Her natural home, she insists, is the “United Synagogue and Bnei Akiva”.

From a traditionally-minded United Synagogue family in Wembley, she attended Yavneh, the local Jewish primary (which merged with another school to become Sinai). Although she gained a place at private South Hampstead Girls’ School — “I was just curious to see if I was good enough to get in” — she opted instead for JFS.

Its residential programme in Israel, then at Givat Washington and lasting five months — enjoyed by her older sister — was a definite draw. It proved to be a “stand-out experience” for her. “I came back speaking fluent Hebrew,” she says. “That’s the way to do it, to immerse yourself in the language.”

But she is not so sure that in “the slightly more protective, helicopter-parent society” of today, families would be willing to send their children away for so long.

Although four of the last five heads of JFS have been women, she can still recall the novelty of selecting a female head. When Jo Wagerman was appointed head in 1985, “I remember I was in a GCSE textiles lesson when it was announced over the tannoy, and you could hear the cheering along the corridors, because people thought they wouldn’t appoint a woman to the job. She was a real powerhouse.” Rachel Fink was Jo Wagerman’s first head girl. (Head boy was Daniel Roselaar, now rabbi of the US shul, Alei Tzion, where she belongs).

Post-JFS, on a Bnei Akiva gap year in Israel, she picked a pomegranate or two on kibbutz, although mostly she worked in the children’s house. While her parents preferred her to take a vocational course at university, she did not get the grades for pharmacy — which she did not really want to do — and was happy to end up studying chemistry at UCL.

She and her husband Stuart married a couple of weeks after her finals and headed off to Israel to settle on kibbutz. “We realised quite quickly that while we loved it there, it was not really a long-term prospect. I wanted to train as a teacher, they said I’d never manage. They thought some quiet little English girl wouldn’t be able to do it.”

Moving nearer Jerusalem, she combined secretarial work at a chemical company with teacher-training at Michlalah, a women’s college. While Michlalah was Orthodox, she did teaching practice at a secular high school, Boyar. “One of the things I liked best at Boyar was it was full of highly educated, non-religious Israelis who knew the Tanach [Hebrew Bible],” she recalls. “They had a totally different take on it but that’s wonderful. Judaism belongs to all of us.”

When the family relocated to Bet Shemesh “along with all the Anglos”, she taught chemistry for seven years in a religious Zionist high school. In 1997, seven girls on a hike were slaughtered in a terrorist attack.

“They were my students, that was my class,” she says. “I didn’t go because I was about to have a baby. It was terrible. One of the girls who was killed was from a family of Russian-speaking immigrants who had been on the ulpan on the kibbutz where we had lived, so I had known them for years.”

Dealing with something like that was “the hardest thing in education. I said after that experience, if I can get through that, I will manage with anything that comes my way.”

In 2001 she and Stuart took the “difficult decision” to return to the UK. Work was taking him abroad for long periods and it reached the point “where we said it’s important for us to be together as a family, however Zionist we were.”

Barely a fortnight had passed since the return of the Finks and their four children to London when she found herself standing in a classroom in Hasmonean as a chemistry teacher at the start of the spring term. Such was the difficulty in recruiting science teachers, she noticed on the girls’ exercise books, the names of several teachers had been scribbled out.

“Some girl said ‘Shall we bother writing your name on the book?’ I said, ‘Mark my words, I shall be here longer than you.’”

Eight years later she had risen to become head of the girls’ school in Mill Hill. For a time, Stuart also taught at the school — he has since moved to the primary sector — and all their children have gone there. Their youngest is due to leave this summer and will, like her older sister, go to a seminary where girls can learn Talmud.

During her Hasmonean career, the biggest change is that “the number of students on roll has increased dramatically”. In September, more than 90 girls will join in year seven, compared to the 60 to 65 a year when she started.

While Hasmonean always does “superbly well” in exams, she says, the girls’s GCSE results last year were “quite remarkable”, their Progress 8 score — reflecting progress from entry to GCSE — putting them in the top five state schools in England.

But she is keen to stress that academic achievement is not the only path to success and during her eight years in charge of the girls’ school, she oversaw an increase in vocational options.

She presided too over a revamp of Jewish studies with “a firm focus on developing textual skills for the girls. Because they go to sem, they need to be well-equipped.” Whereas their study of biblical commentary used to be mainly confined to Rashi, now they explore more widely. “The best comment I got from a student class was that it was harder but more rewarding. ‘I like how all the commentators disagree with one another, so I can have my own opinion’,they told me.”

Two other developments give her particular pride: firstly, outreach to other schools. “We were doing it long before the term ‘British values’ ever appeared on the school radar.”

A few years ago she took an interfaith course, the Cambridge Co-Exist Leadership Programme, making contacts which led her to a partnership with the Islamia Girls School.

As well as reciprocal visits to each other’s schools, the girls have taken part in joint Mitzvah Day activities. She has also forged links with nearby Copthall Girls’ School and introduced volunteering for girls at an afterschool homework club locally for the children of Somali refugees. “That’s been going for six or seven years. It’s wonderful. We have got Jews, Muslims, Christians all together, everybody’s getting on beautifully.”

When a few years ago, a group of 13-year-old Hasmo girls won a competition run by the Wings for Hope charity, some people wondered if it would be feasible for the school to accept the prize — a 10-day trip to India. “I said ‘How am I not going to send them?’ We had the most amazing week.”

The other “big thing” was work on mental health. Four years ago, she was at a Partnerships for Jewish Schools meeting for heads discussing future priorities. “People were talking about finance and succession planning and recruitment. I put my hand up and said, ‘Mental health among students’.”

Pupils may have been grappling with issues before but schools have increasingly become aware of their incidence, she explains. As well as helping to initiate a Pajes programme to train teachers about mental health across Jewish schools, at Hasmonean she took such initiatives as recruiting its first emotional wellbeing practitioner last year. “It’s not a stigma to talk about mental health at Hasmonean and that’s our biggest achievement.”

Her husband — “my greatest cheerleader” — prompted her to go for the JFS job. “The opportunity to lead the school that gave me so much as a student was an absolute dream come true. So I thought, why not go back to where it all began?”

At 48, she has many years still to give to Jewish education. Every student must find their own connection to Judaism, she says. “For some people, that’s religious observance, for others, spirituality, for some a connection with Israel. It’s many different things to many different people. For some, it’s a combination of all those things.

“I have a quite holistic approach to education. It’s more than just a set of exam results. It’s about who you are going to be as a human being, what can you give to society, how can you help your community and how do you interact with the world around you.”