Her stepmother says the person who killed pop star Kirsty MacColl will never be caught.

Kirsty was famous for songs like “Fairytale of New York” and “A New England.” She died in 2000, when she was 41 years old, when she was hit by a powerboat while diving off the coast of Mexico with her 13- and 15-year-old sons.

The boat was moving quickly and illegally in a diving area that wasn’t meant for people. Guillermo Gonzalez Nova, the multimillionaire president of a Mexican supermarket chain, was in charge of it, but one of his employees took the blame and was fined $2,240 instead of going to jail for 34 months.

Justice For Kirsty was led by Kirsty’s mother, Jean Newlove.

Peggy Seeger, 88, was married to Ewan MacColl, Kirsty’s dad, from 1977 until he died in 1989. They were married for 58 years. “Kirsty’s death was a complete and utter criminal tragedy,” she said.

“A man who shouldn’t have been there put out a bright light.” He tried getting someone else to take the blame.

“It’s like how our government works: they say one thing, then horrible things happen, and they find a way to get around it. That’s what they did.

“Power does that.” What it did to her sons’ lives for good.

She said, “No” when asked if Kirsty would ever get justice. Her mother was the only one who could have gone after them, and she did try.

“Partly because she had been married to Ewan for a while, she knew that you can’t get to powerful people when they hide behind their power, especially when they’re in a different country.”

Peggy, a seasoned singer and musician who will play at the Cambridge Folk Festival on July 28, says this about Kirsty: “Ahhhhhh.” She was my daughter-in-law. We really should have worked together. She was very smart. She could do many things. She had great ideas.

“I believe she would have flown.” However, she was scared to go on stage. “For a while, she beat it.”