 Ansell educated at King's High School for Girls there, Ansell qualified at the University of Birmingham in 1946 and did her post-graduate training at the Royal Postgraduate Medical School in Hammersmith.In 1951 she was appointed as registrar to Professor Eric Bywaters at the Canadian Red Cross Memorial Hospital, Taplow, Buckinghamshire, where she conducted research on heart disease in rheumatic fever.In 1962, she was appointed consultant clinical physician in rheumatology at Taplow.