She was born in Edinburgh, and lived there with her mother Dorothy Nesbitt, father William Miles Johnston, otherwise known as Bill, her brother Tony and sister Pat. Cecile was named after the distinguished Kirkcudbright artist Cecile Walton.

The young Cecile Johnston attended St Trinnean’s school in Edinburgh, a school she loved. It was a most unusual school for its day as it practised a revolutionary method of education called the Dalton

system. Here the emphasis was on self-imposed, rather than school-imposed, discipline, which led to it being said that St Trinnean’s was the school “where they do what they like”. This was one of the probable cornerstones to the unconventional life that Cecile lived.

She attended St Trinnean’s along with Tony and Pat before being evacuated during the war to Kirkcudbright. Her parents were artists who had spent their holidays in Kirkcudbright, in the Greengate Close, where artists

Jessie King and E A Taylor lived and worked. The family had a beach hut at Carrick where they spent happy summer days.

Cecile’s parents moved permanently to 15 Castle Street, Kirkcudbright, in 1940, while renting their house in Edinburgh. They lived upstairs, and at street level opened a shop known as The Crafts. Bill was a distinguished watercolourist with a particular reputation for painting wildlife.

Kirkcudbright was a magical place of light and beauty, and it was believed that an artist’s training was not complete until they had spent time there. In 1941, through a shared passion for art, a soldier posted there befriended Cecile’s family. As a bit of fun, he drew sketches of the schoolgirls, Cecile and Pat. This may seem unremarkable enough, but the soldier turned out to be Ronald Searle – the artist and cartoonist. The sketches were eventually published and evolved into well-known characters and famous films. To this day, Ronald feels a responsibility for what Cecile suffered as a result of that early fun, although her family suspect she was always secretly proud to be “the original St Trinian’s school girl”.

During the war, Cecile was in the WRNS. She organised art and craft classes, and was latterly stationed at Bletchley Park where the Enigma code was deciphered. Military intelligence gleaned from this source was instrumental in shortening the war in Europe by as much as two years. The family will never know exactly what part she played in this story, as Cecile was fiercely loyal, to people as well as to her country, and never talked about her time there.

In 1947, Cecile went to study at Edinburgh College of Art and her parents gave her use of two rooms in the family house. Right from the start Cecile showed her incredible artistic and creative talents. As her friend Ronald Searle said about her: “She was born with a paintbrush in her hand.” She graduated with a Diploma in Arts in Drawing and Painting in 1950 and eventually became president of the Scottish Society for Women Artists. During her professional career, she exhibited in the RSA, the RSW and the SSA, and was an elected member of the SSA and SSWA, and by invitation to the Arts Council. She was a regular exhibitor for many years in the Edinburgh Festival Fringe with the Chessel Group.

On leaving college, Cecile taught at the city’s Ainslie Park School, and later at Moray House College, where she was responsible for ceramics, and researched and published work in environmental education, and art in the education of children with special needs.

Each year for more than 30 years, she organised a multi­disciplinary course to Glenmore Lodge in the Cairngorms and took students, including many overseas visitors, there for a unique learning experience. She was part of an enthusiastic team who combined traditional subjects of biology, geography, art, history and maths with the specialist subjects of the Glenmore staff, including sailing, canoeing and rock climbing.

For most of the students involved, it was the highlight of their college course with lasting effects on their attitude to the environment. Enduring friendships were formed across subject and national boundaries, especially during the infamous ceilidhs at which Cecile, even in her 60s, astounded students with her physical fitness and flexibility.

She is survived by her husband, Finlay; daughter, Cecile: and grandchildren, Sean and Amy.