Emma Cecilia 'Ida' Darwin, born 1854, married Horace Darwin (1851-1928), fifth son of Charles and Emma Darwin. They had three children: Erasmus (1881-1915) who died at Ypres during the First World War, Ruth Frances [Rees-Thomas] (1883-1973), and Emma Nora [Barlow] (1885-1989). The Darwins lived at ‘The Orchard’, a large house on Huntingdon Road in Cambridge.
In 1883 Ida joined a group mainly of wives of Cambridge University academics to found the Cambridge Association for the Care of Girls (from 1956-1985 the Cambridge Association for Social Welfare). The Association offered to help girls living in dangerous circumstances, giving them training and finding them work in domestic service. In 1908 she and Florence Ada Keynes (1861-1958) founded the Cambridge Association for the Feeble-Minded (from 1921 the Cambridgeshire Mental Welfare Association) to help to put into action the recommendations of the 1908 Report issued by the ‘Royal Commission for the Care and Control of the Feeble-Minded’. The report provided the first clear legal distinctions between people with a mental illness and people with a learning disability or brain injury. Ida remained President of the Cambridgeshire Mental Welfare Association until 1942, and this contact with the vulnerable inspired her to campaign for the passing of the Mental Deficiency Act of 1913 which required local authorities to maintain institutions and supervise community care. In 1913 she was elected to the Executive Committee of the United Kingdom’s first national mental welfare organization, the Central Association for Mental Welfare (CAMW), led by Dame Evelyn Fox. Ida was Vice-President from 1917 until 1927. From 1922 to 1927 Ida also served on the committee of the National Council for Mental Hygiene; in 1947 this merged with CAMW and the Child Guidance Council (established in 1927), to become the National Association of Mental Health, the leading UK mental health charity now known as Mind.
In 1924, Ida and Horace Darwin and Dame Ellen Hume Pinsent donated £5000 to Cambridge University to endow a scholarship for "original research into any problem which may have a bearing on mental defects, diseases or disorders." It continues today as the Pinsent-Darwin Studentship in Mental Pathology, named after their sons who died in WW1. Ida died in July 1946.