Haslett became vice-president of the International Federation of Business and Professional Women in 1936 and president of the organisation in 1950; and she was the first woman to chair a government working party – the Board of Trade's Hosiery Industry Working Party 1945–46.
Haslett held positions as vice-president and then president of the International Federation of Business and Professional Women in 1936 and 1950, respectively; she was also the first woman to chair a government working party – the Board of Trade's Hosiery Industry Working Party from 1945 to 1946.