As an autodidact in her twenties, having only a British high-school formal education, in the U.S. she gradually advanced, by virtue of groundbreaking citizen activism, into the roles of university lecturer and chair-holder, as well as that of advisor to corporations and government agencies.

She authored several books including Building a Win-Win World, Beyond Globalization, Planetary Citizenship (with Daisaku Ikeda), and Ethical Markets: Growing the Green Economy.

[2][3][4][5][1] Henderson was born on 27 March 1933, in Bristol, Somerset, England, the daughter of Kenneth and Dorothy May (née Jesseman) Mustard.

Her many complaints to city hall went nowhere, prompting her and Carolyn Konheim, another concerned parent, to form Citizens for Clean Air.

The group made several early advances in clean air activism by lobbying for local, state, and federal pollution legislation.

[1][2] In 1996, she married Alan F. Kay, an internet pioneer and social entrepreneur who was the founder of the electronic Wall Street trading platform AutEx.