Erin was born in London in 1957, to Roger Bannister (athlete and neurologist) and Moyra (artist).
Erin lives in Oxford with her scientist husband Alain Townsend and they have five adult children.
She was educated at St. Paul's Girls' School, London and at the Ruskin School of Fine Art, Oxford, and then won a scholarship to the Royal Academy Schools. Important influences were Peter Greenham and Leonard McComb and she was awarded David Murray landscape prizes in 1976 and 1979.
Erin first showed at the Thackeray Gallery, London in 1981. Since then she has exhibited widely in both mixed exhibitions in London (RA, National Portrait Gallery, New English Art Club, Burlington Fine Art) and in Oxford.
Erin has had solo exhibitions in London with Sally Hunter Fine Art in 1993 and 2007, and again in 2013 at the Medici Gallery, Cork Street, London.
She was resident artist at Garsington Opera in 2005 and 2010, and at Lucy Properties, Oxford. She was an artist in residence at The Story Museum, Oxford. Each residency culminated in an exhibition.
St John’s College, Oxford University Press, Oxford High School, The Radcliffe Infirmary, Vincent's Club Oxford University, Paintings in Hospitals, the Bridgeman Art Library and the Ashmolean Museum Oxford. She has paintings in many private collections in the UK, France, Switzerland, USA, Australia and South America.