Betty Rea was born in London in 1904. Her father was Dr. Arthur Bevan and her mother's maiden name was Barnardo; Dr.Thomas John Barnardo was her great-uncle.
She was educated at Downe House School (in Kent at that time) and began to study painting at the Regent Street Polytechnic in 1922, almost at once changing to sculpture and transferring her studies to the Royal College of Art in 1924. Her teacher there was Ernest A. Cole. Henry Moore was a student teacher at the RCA at that time, and became a friend.
During the 1930s, partly influenced by her friendship with Professor John Desmond Bernal, Betty Rea was greatly involved in anti-fascist, leftwing politics. From 1934 to 1936 she was secretary of the Artists' International Association, founded in 1933, this organization sought to oppose imperialism, fascism and colonialism through art.
For most of the war, Betty Rea taught painting and model-making in evacuated children's homes in Huntingdon and the surrounding country. She set up home with her colleague, Nan Youngman, first in a caravan in the grounds of Hinchingbrooke House, then in Godmanchester, and in 1946 at 'Papermills' in Cambridge. The children's paintings from this time were included in several British Council exhibitions sent abroad and some are illustrated in Herbert Read's "Education Through Art".
Betty Rea died in 1965.
Her 1959 Stretching Figure (bronze resin), was described by Gillian Whiteley as "expressing the diverse emotions, activities, and grace of youth". It is held by the Herbert Art Gallery and Museum, Coventry.