It was after her second arrest, as she faced a possible criminal record that Derek, Barbara Froomberg’s husband decided that he could no longer support his wife in her charitable efforts. It was 1973 and the protest organisation, The 35s, were demonstrating against the persecution of Jews in the Soviet Union. Barbara had put her characteristic energy and zeal into the project and being chained to some railings meant she had to contact Derek, yet again, to pick up their young sons from school while she was “bound over to keep the peace”.

It was not only charity work that Barbara put her energy into. When her third baby, Karen, had reached the age of five, she felt she wanted to help provide financial support for her young family. She had heard that there was a small business for sale providing plasters and bandages and when her mother, Reva, lent her the money to buy it she set up in business, despite having little experience of commerce.

Derek converted their Hendon garage into an office, complete with the dodgy typewriter that was included in the deal (it made a hole in the paper every time the “o” was pressed) but almost immediately it was apparent there really was only one proper client, Bovis Construction, and turnover was just £71 a month. Her friends rallied round, and soon became the best equipped group of first aid box owners in north London. This perked up the company figures, but a lot more was needed.

Fortunately, the Health and Safety (First Aid) Regulations 1981 Act had recently been passed, requiring all construction sites to have first aid boxes with suitable equipment — as well as trained personnel. So Barbara, with a portable stretcher on her back, a first aid box in her hand — and plenty of chutzpah — visited some of the large London building sites to sell her wares.

The most obvious first target was the Nat West Tower which was then being built. She remembers getting out her car and asking if she could speak to the first aid buyer. “Oh,” said a builder, “you mean Dave” She said “yes, that’s who I want, Dave”, although she did not have the faintest idea who Dave was. Anyway, Dave turned out to be extremely kind and she got the business of supplying them with all their first aid needs, a really good step forward for her little firm.

When she next met Dave, he said that they needed some light liquid paraffin for cleaning and asked if she sold it. She said “sure” although she had no idea what he was talking about and certainly had no supplies. Where to buy it from? She had become friendly with three helpful pharmacists and they offered to help her get some quickly to fulfil the order.

Business increased and it became apparent she would need funds behind her to aid growth, but it was a time when there was still prejudice against women in business. In response she put on her best outfit and went to visit her bank manager. One of his first questions was what collateral she had. She did not understand what this meant and the manager replied “Mrs Froomberg, how can you possibly get an overdraft if you have no idea about business?” She replied, “Because, I want to learn”. He turned her away, making Barbara simultaneously upset and determined.

Happily, Derek introduced her to his bank, who were more helpful, and before long Barbara had a secretary, had bought a van and employed a delivery driver (who crashed the van almost immediately). Setbacks, she began to realise, were all part of a business life.

It was a few years later that she was asked to visit a building site in the East End with the building manager. She remembers walking endlessly around an enormous plot until at last she asked in exasperation “What do you want from me?” She was in a hurry as she needed to get home to do some packaging to send out supplies.

His reply changed her life. “We are going to employ 6000 people here and would like you to quote for supplying doctors, nurses, safety officers — in fact everything”. It was Canary Wharf.

By then Barbara’s oldest son, Robert, was 23 and he said “You really can’t run this business on your own anymore. I am coming in to help”. He had been to university and studied accountancy, law,and hotel management, and was at the time working for Trust House Forte.

They realised too that it was no longer feasible to work from home, especially because the neighbours were getting fed up with big delivery trucks driving up at 5am most days. They looked for premises and eventually found a little shop at Kelly’s Corner in Mill Hill.

The next issue was how to get hold of some nurses. Barbara decided they needed to involve an agency but that didn’t work out and so they set up their own nursing side of the business, soon followed by another offshoot of their company, offering first aid training.

It was not all plain sailing, especially when their biggest client went into liquidation, owing Barbara thousands of pounds. It could have been the end of everything — but sheer dogged determination enabled her to survive.

Today, her company Safety First Aid is the UK’s biggest supplier of first aid supplies, with a healthy multi-million-pound turnover. Robert runs the company with Barbara taking a back seat as chairwomen.

Her beloved husband, Derek, died nine years ago but Barbara is as active as ever. Her middle son Andrew lives in America, while Karen is not far from her mother in north London.

I just managed to fit this interview into her busy schedule, between a swim, a special treat for one of her many grandchildren - and a drive from London to Brighton to see her brother, Peter.

At 86, Barbara it seems, is not going to stop her busy lifestyle anytime soon.