Last year, Sally Heddle became one of the first people to undergo pioneering brain surgery while fully conscious.

The operation - possible because the brain feels no pain - was the latest manifestation of the music and English teacher’s life-long view that illness and adversity are opportunities to help others.

Sally Bristow was born in Hastings in 1936. Her parents were both enthusiastic singers and Sally was singing solos at the church fete before she had finished primary school.

After school, she read English and music at London’s Royal Holloway College. While acting in college plays, she met a trainee teacher called Geoff Heddle; they married seven weeks after she graduated.

She had initially hoped to go to South Africa to campaign against apartheid. But her mother died during her first year at university, leaving her father distraught. After that, Sally was reluctant to leave the country.

Teaching seemed a natural alternative. Her first job was in the English department at Hampden secondary modern in Hertfordshire. Two years later she moved to nearby Northwood College, before taking time out to raise two children, Richard and Elisabeth.

It was a very deliberate decision to teach English, rather than music. She remained an enthusiastic singer, performing solos in local choirs and quartets. But, she said, she did not want her musical pleasure to be tempered by work concerns.

This changed in 1970, when the couple moved to Bromley and Mrs Heddle applied for an English-teaching post at Stratford House school. The headteacher called shortly afterwards: they would not be appointing her to the English department. But the head of music had just handed in his resignation. Would Mrs Heddle like that job, instead?

She accepted and spent the next few years building up Stratford House’s reputation for music. School choral groups began to perform at local festivals and she set up a pupil-parent-teacher choir.

Then multiple sclerosis hit. Mrs Heddle tried to carry on teaching regardless: on one occasion, she delivered an A-level lesson from her sickbed, pupils gathered on the bedroom floor. Eventually, however, she simply lacked the strength to continue.

By 1980 she was wheelchair-bound. But she saw her disability merely as something to be overcome: a challenge that she must surmount in order to get on with her life. The ability to help others had been a driving force in her teaching career. Now she began to look at different ways to do this.

Thus began a second career, this time in charity work. She served as chair of Bromley Arts Council, looking in particular at ways to include disabled artists. Indeed, much of her charity work focused on improving life for disabled people: she established a sailing club that enabled them to serve as crew members; she developed a disabled counselling service; she served as chair of the Dial-a-Ride scheme.

Following the couple’s move to the Orkney islands in 2001, she also trained as a reader in the Church of Scotland. Unable to ascend to the pulpit, she addressed her congregation from the aisles. “I don’t preach,” she said. “I lead worship.”

In 1992 she was awarded an MBE for her charity work. She was not one to boast, however: there was no time for bragging when there was work to be done.

A tracheostomy operation in 1984 had allowed her to breathe more easily, but left her unable to sing. From then on solos were limited to her own home. At no point, however, did she say “Why me?” Through the progression from one crutch to two, to wheelchair, tracheostomy and, in 2009, breast cancer and a mastectomy, her focus was always: here is a problem, now how do I solve it?

This was her attitude when, in May last year, she suddenly found herself unable to speak. Her life had been built on communication, whether singing, acting, teaching or delivering a sermon. There needed to be a solution.

Doctors diagnosed a brain tumour and offered her a new form of treatment. They would operate while she was still awake. Once again, Mrs Heddle saw an opportunity to help others and enthusiastically volunteered. As the surgeon removed the tumour, she recited nursery rhymes and did simple mental arithmetic. Her words helped the doctor determine where to cut.

She was never under any illusions. She knew that the operation was not a cure. But quality of life was what mattered: in the time that she had left, she wanted to be able to speak and sing.

Sally Heddle died in December, aged 74.