Her legacy was one of deeds, words and images. Morgan is widely credited with coining the term “herstory”, the feminist reworking of “history”, and popularizing the clenched fist/female symbol icon of the liberation movement. Her poem Monster, with such lines as “I want a women’s revolution like a lover/I lust for it” was quoted at feminist rallies and beyond. Her poem Arraignment helped capture the movement’s embrace of the late Sylvia Plath and condemnation of her husband, poet Ted Hughes, whom Morgan and others blamed for Plath’s suicide in 1963. Morgan’s rhyming couplet “I accuse/Ted Hughes” inspired the title for Sonic Youth’s song J’Accuse Ted Hughes.

Labeled an “anarchist housewife” in one government report, Morgan confronted the establishment, left and right. In 1970, she and fellow protesters were arrested and jailed after occupying the offices of the avant garde Grove Press, whose owner, Barney Rosset, was fighting employees’ efforts to unionize. In the widely reprinted 1970 essay Goodbye to All That, she called out activists and libertines from Abbie Hoffman and Hugh Hefner to Dave Dellinger and the music group the Fugs.

In her personal life, Morgan had male and female lovers and was married for more than 20 years to the gay poet Kenneth Pitchford, with whom she had a son, the musician, activist and record company executive Blake Morgan. She once described her marriage as a “two-member commune” and was so resistant to labels that she remembered being “straight-baited” by feminists who thought she should be a lesbian and chastised by conservatives who assumed she was a lesbian.

In her 2001 memoir Saturday’s Child, she expressed joy and amazement at how her life had turned out and how she was able to retain “a threadbare, somewhat surreal sense of humor”.

“Put that in your apple pie and smoke it,” she wrote.

Besides Saturday’s Child, she completed more than 20 books, including The Word of a Woman: Feminists Dispatches and the poetry collections Monster and Dark Matter. She followed Sisterhood Is Powerful with Sisterhood Is Global (1984) and Sisterhood Is Forever (2002), featuring such contributors as Steinem, Simone de Beauvoir and Eve Ensler. For several years, she was editor-in-chief of Ms magazine.

In 1984, she was a founder of an early feminist thinktank, the Sisterhood Is Global Institute. In 2005, she, Steinem and Fonda launched the Women’s Media Center, which has a mission to support “the visibility, viability and decision-making power of women and girls in media”.

More recently, she hosted a syndicated radio show and remained active despite being diagnosed with Parkinson’s, which inspired several poems and a TEDWomen talk in 2015.

In a different era, she might have been just another forgotten child star. Born in 1941 in Lake Worth, Florida, and raised in New York, she never saw her father while growing up and was told – falsely – by her mother that he was dead. Her mother also shaved a year off her age, claiming she was born in 1942, to make her early public career seem even more impressive.

She would meet some of the era’s biggest stars, from Abbott and Costello to Sal Mineo, and was popular enough to inspire such commercial tie-ins as Robin Morgan dolls. Magazines described her as “unspoiled” and “courteous” and “the ideal girl-next-door”, immune from “violent outbursts of antagonism against established society”.

As she recalled in Saturday’s Child, producer Dan Ehrenreich squeezed her shoulder so hard that Morgan could feel his fingernails. He turned her microphone away and eventually placed his hand over her mouth.

“I realized that I loved and respected that child who fought back in what was the first political act I recall ever daring to make,” Morgan wrote.