My friend Marianne Ferguson Rice, who has died aged 93, was a teacher turned social worker who in later life worked with a disability charity in São Paulo, Brazil, before returning to Britain to serve Quaker causes.

Born in Lydney, Gloucestershire, she was the youngest of five children of Ruth Perry, a housewife, and Alan Ferguson, who had been a tea planter in Ceylon (now Sri Lanka). Marianne initially had a privileged upbringing with a nanny and servants, but when she was six most of the family’s money was lost in the Depression.

They moved house, took in lodgers and made do, but Marianne was deeply affected. Suddenly uprooted, she missed her beloved nanny, had a difficult relationship with her mother for many years, and struggled with self-confidence. In 1940 her only brother, Malcolm, was killed during the second world war, and 10 months later her sister Monica also died.

After school in Cheltenham, Marianne trained as a teacher at Charlotte Mason College in Ambleside, Cumbria, then spent a brief period abroad before being summoned back to set up a Montessori school in the parental home. She ran it successfully for seven years, working with great diligence, but was miserable doing so. She did not consider herself a good teacher, nor did she want to live at home, although she felt obliged to do so.

In 1959 Marianne went to Canada to teach in Ontario and Ottawa, where she made many friends. Subsequently she returned to England to become a social worker, and was employed by Brent council in north-west London. In 1963 she married Bill Rice, an accountant and widower with grownup children who provided the unconditional acceptance that allowed her finally to become her own person. Bill also introduced her to Quakerism and she served as clerk, overseer and treasurer at her local Quaker meeting house in Hampstead, north London.

After retiring Marianne volunteered with a disability charity, working in the favelas of São Paulo. When she left, to return home, she was presented with a banner inscribed: “Dear Marianne, we pay homage to your noble work done in Brazil.”

Back in Britain she supported a dying friend in Edinburgh and finally decided to settle there. She spent her last 20 years in the city, serving the Quaker central Edinburgh meeting, working tirelessly for Campaign Against Arms Trade and establishing an Alternatives to Violence Project.

Marianne was devout but also politically engaged, and was cherished by a large circle of friends.

Bill died in 1979. Marianne is survived by six step-grandchildren and by a niece, Sonia.