She got noticed from the moment she left McKeesport, Pa., in the late 1960s (one of eight children; her father was a steelworker; her mother, a waitress). Cheryl was whip-smart, charismatic, steel-willed — and determined, as she put it, to "agitate and inform."

"You faced a choice," recalls Tom Taylor, a fellow activist, about meeting Cheryl for The first step time. "Either follow — or get out of the way."

Her editorials against the Vietnam War in Detroit's Wayne State College paper led then-FBI Director J. Edgar Hoover to brand her a security threat (she kept the note as a badge of honor).

I was a cub reporter at LIFE magazine, when, in the early '80s, Cheryl swooped in like a tiny force of nature: energetic, restless, full of confidence and swagger (if anyone can swagger at 5 feet tall).

"We all trailed behind that little woman," recalls writer Anne Fadiman. "She was always full throttle, no brakes."

Cheryl wrote about celebrities, but also famine in Ethiopia and poverty in Haiti. And like too many of us in those days, she thought she was bulletproof; she chain-smoked three packs of Benson & Hedges Slim Light 100s a day.

We envied her knack for becoming close friends with the stars she met: Willie Nelson, Maya Angelou, Billie Jean King. But it was the powerless — the vulnerable — that Cheryl really cared about. In African deserts and urban ghettos, she sought out the children. In 1985, she raised $150,000 and turned her LIFE story about Seattle street kids into the film "Streetwise." A few months later, wearing a glittering blue dress (none of us had ever seen her wear one), she was strutting down the red carpet, nominated for an Academy Award.

We were so envious, we could have killed her. But Cheryl's friends knew that underneath that brash, name-dropping exterior was an enormous, generous heart.

For Cheryl, trumpeting the plight of children was a mission so strong it had to come from somewhere deep inside. Few of us knew just where — until she reported and wrote a powerful LIFE story on childhood sexual abuse. It began with a startling first-person account: Cheryl's story of how she herself had been a victim.

But storytelling, she decided, was not enough to change the world. So Cheryl gave up journalism for Yale Law School, then moved to Nevada City, Calif., to become a lawyer. She fought for children in custody cases, entering, as she said, "this self-imposed Witness Protection Program that has become my life since I inexplicably fell in love with the law."

In fact she had two loves: the law and motherhood. Cheryl gave birth to a daughter, Jessie. Single motherhood became her passion. (Her relationships with men — including one marriage — did not last.)

Then, in 2000, the first dark cloud — Cheryl was diagnosed with breast cancer. She beat it into remission. But five years later, the cancer was back — this time in her lungs. It spread to her liver, her lymph nodes, her bones. Cheryl fought back with chemotherapy and radiation, and then flew to Hawaii, to a clinic specializing in "integrative medicine."

She gulped herbs and sat under blazing lamps called Beam Ray machines. She kept her friends posted on every pill and chemo drip with notes on a Web site called "the Little General."

It surprised no one that with her own survival in the balance, Cheryl felt compelled to save everyone else. She badgered me to produce a documentary on that Hawaii clinic for ABC.

"How many folks do you have to pitch this to, to get a green light?" she e-mailed impatiently. She worried about Peter Jennings. And she organized a special screening of "Streetwise" to raise money for the kids in Nevada City's courts — her kids. On a Friday afternoon in late October, Cheryl was out on her porch, laughing and entertaining visitors. Three days later, she was dead.

Her funeral was packed with friends — lawyers, judges, prosecutors and hippies. Maya Angelou wrote a poem, and so did the children down at juvenile court.

Cheryl's daughter, Jessie, now 16, said, "I think my mom told her story, and then she left."

One friend recalled that back at her childhood home in McKeesport, the electricity always seemed to be getting turned off. Cheryl wanted her own home, where the lights would always be on. So she built a magnificent house in the woods. After her burial, everyone gathered there. The wine, and the stories, flowed until midnight.

"She never lost her passion for truth, her curiosity, her toughness," said Claudia Dowling, a LIFE colleague. "And she never forgot old friends. Everyone, whether her name was Liza or not, was welcomed to her palace in the woods."

I didn't learn until later that Cheryl had failed at one challenge, something she rarely talked about. Try as she might — stopping for weeks and even months — she never could quit smoking.

A few months earlier, as the cancer tightened its grip, Cheryl had written on her Web site: "I hate self-pity, in others but especially in myself. I will not tolerate it. I lived in London and the cafes of the Left Bank of Paris. I worked on salmon seiners and marked timber and was not a bad mechanic. And I had more than my share — and probably your share too (sorry) — of many torrid, wonderful love affairs. This life has been quite a ride. So don't feel sorry for me."

And then she added: "But one last thing. I have decided the doctors are wrong. I intend to be one of those people who survive this. So don't count me out yet."

I never did.

Chris Whipple is a producer for ABC's "Primetime."