She was born Stella Myers on 5 June 1883 in Edgbaston, Birmingham, the daughter of George Myers (b 1841) and Flora Wertheimer (1851–1921). She was the great granddaughter of Chief Rabbi Akiba Wertheimer, and great niece of German philosopher Constantin Brunner.
After Edgbaston High School she went to Girton College Cambridge to read Natural Science, graduating in 1905. Following her marriage in 1908 she went on to read medicine at the London School of Medicine for Women. She obtained a Diploma in Public Health in Cambridge in 1921.
After qualifying as a doctor in 1917 she held junior posts at the Hospital for Sick Children, Great Ormond Street, the Victoria Hospital for Children, and the Italian Hospital, before being appointed anaesthetist to the British Red Cross Hospital at Netley in 1918. She was a keen supporter of the Save the Children Fund and served on its council. She retired from public health service and became interested in medical psychology and was appointed psychotherapist to the Tavistock Clinic and the West End Hospital for Nervous Diseases.
She lived at Strand Green House, Number 1 Strand-on-the-Green, Chiswick, from about 1923-1932 where her houseguests included the writer "Elizabeth" May Beauchamp, author Margaret Kennedy who used Strand Green House in her book The Constant Nymph, and sculptor Joseph Armitage.
She opened the first local child welfare clinic at Strand on the Green School. From –32 she represented South East Southwark on the London County Council.
She was Parliamentary Labour Candidate for Hackney North in 1924 and for Brentford and Chiswick in 1929. She died on 16 September 1954 in Menton, France aged 71.
Churchill took a strong interest in infertility, sexually transmitted diseases, and eugenics and was a member of the Eugenics Society serving on its committee from 1931.
