Marianne Edwardine ("Edda") Fannin, teacher, botanical artist and plant collector, was the twelfth child of Thomas and Ellen Fannin, who arrived in South Africa from England with their large family in 1845. After two years in Cape Town they moved to Natal and settled in the midlands, some 30 km north-east of Pietermaritzburg, on a farm, which Thomas renamed The Dargle. They were one of the earliest settler families in the region and derived their income mainly from cutting timber on the farm. Edda showed a talent for music from an early age and taught herself to play a chamber organ. She had a particularly close relationship with her brother George, who was an enthusiastic plant collector. Edda pressed and made water-colour paintings of plants he had collected, for W.H. Harvey*. She also collected specimens herself. Harvey mistakenly assumed that she was George's wife and attributed the finds to "Mrs G. Fannin". He named the species Streptocarpis fanniniae and the orchid Disperis fanniniae after her.
After her father's death in 1862 Edda lived with family members in Pietermaritzburg. In May 1869 she married Reverend Eustace W. Jacob, but he died in 1871. Having gone to England either with her husband or after his death, she trained as an organist in Winchester Cathedral and studied painting at the School of Art in South Kensington, London, before returning to Natal in 1875. After teaching music and drawing at the Diocesam School for girls in Richmond, Natal, she moved to Pretoria in January 1879, teaching art and music at the Girl's School. Later that year she married Reverend (later Archdeacon) Alfred Roberts. After a difficult time during the siege of Pretoria in 1881 they moved to Potchefstroom, where they remained for 15 years. The couple had two sons, Noel* and Austin*, of whom the latter in particular made major contributions to South African ornithology and mammalogy. At the outbreak of the Anglo-Boer War in October 1899 Edda and the boys went to Natal, but she returned to Potchefstroom in 1901. After the war she played an important role in rescuing from oblivion many cemeteries of soldiers' graves in the north-eastern Transvaal. By 1913 she resided in Wakkerstroom.