Susila Bonnerjee (known as Susie) was the daughter of W. C. Bonnerjee and his wife, Hemangini. Born in India, she first moved to England as a child and lived in the family house in Croydon. Her parents travelled between England and India frequently with the intention to educate all their children in England. Susila attended the Croydon High School for Girls and then gained admission to Newnham College, Cambridge in 1891 (as her sister had). Susila was awarded a second class in her Part 1 exams in 1894. She then joined the London School of Medicine for Women, and was attached to the Royal Free Hospital. Susila gained her MB degree in 1899.

A little later she returned to India and worked in Calcutta and at the St Stephen's Mission at Delhi. After her father's death in 1906, Susila took up research work at Cambridge. She was Demonstrator of Physiology in Balfour Laboratory, Newnham College, 1910-12, and was in private practice at Ealing for five years. In 1911 she became Secretary of the Indian Women’s Education Association, which was involved in raising funds to educate Indian women in England in methods of teaching. During the war, in 1915, she went to Calcutta but returned to England in early 1916. She left for India again in 1918 due to declining health and died in September 1920 in Lahore.

Janaki Agnes Penelope Majumdar was the daughter of the Hemangini and W. C. Bonnerjee, the first president of the Indian National Congress in December 1885. Born in Calcutta, in June 1886, Janaki, her mother and siblings settled in England from 1888. They soon moved into a house they named 'Kidderpore' in Croydon. Janaki spent 1893-5 back in India and then returned to England and went to Croydon High School for Girls.

She studied at Newnham College, Cambridge, in 1904, and was the first Indian woman to receive a degree in Natural Sciences. Following the death of her father in 1906, 'Kidderpore' was sold. Janaki began a teacher's training course at the London Day Training College in 1907 and did voluntary work at the Charity Organization Society's Newington Branch. In 1908, she returned to Calcutta with her mother and met P. K. Majumdar. He had studied at Birmingham University and trained as a barrister in London. They were married in 1909 and lived in Calcutta. She returned to London following her husband's death in 1947.

In 1935, Janaki wrote a family memoir about her childhood, her father and her husband, with a major emphasis on her mother, Hemangini. It tells of a South Asian family living in England in the late nineteenth and early twentieth centuries. This memoir, Family History, was edited by Antoinette Burton and published in 2003.