Molly Lee is talking to me about the tales her aunt Nelle, known to the world as Harper Lee, would weave for her when she was a little girl. She was just a great storyteller, says the 77-year-old from her home in Alabama.

That's an understatement if the success of Harper Lee's Pulitzer-prize winning novel To Kill A Mockingbird is anything to go by. Since its publication in 1960, when it was an instant hit, the book has sold more than 42 million copies worldwide. Based around the story of Tom Robinson, a black man falsely accused of rape, it's told through the eyes of two white children, Jean Louise 'Scout' Finch and her brother Jem - and is often described as an American classic.

But at the point Molly is describing, before the world had heard of Lee, she was simply an aunt enchanting her niece with stories, often by riffing on one of her favourite authors, the British novelist Daphne Du Maurier. The stories that she told me, she would make them up but they all seemed to be based around, 'It was a dark and stormy night'... It seemed to me they were always on the moor and she would just take me into the dark, Molly says.

Molly's cousin is 77-year-old Ed Lee Conner. His earliest memories of his aunt date back to the late 1940s, when he was tiny. She sang to me in a way that was very funny, he recalls. And I laughed.

The cousins are sharing their memories of their aunt - who died in 2016 - on the eve of the publication of a new book, The Land of Sweet Forever. It's a series of newly discovered short stories Lee wrote in the years before Mockingbird, as well as previously published essays and magazine pieces. Ed explains: I knew there were unpublished stories, I had no idea where the manuscripts of those stories were. They were discovered in one of his aunt's New York City apartments after she died, a time capsule from the start of Lee's career which help explain how a young woman from Alabama became a best-selling author whose work addressed the turbulent issues of her age.

Molly is very pleased that the stories have been found. I think it's interesting to see how her writing evolved and how she worked on her craft, she says. Even I can tell how she improved. Some elements will be familiar to fans of To Kill A Mockingbird. Versions of Jean Louise Finch appear, although she hasn't gained her nickname Scout yet. In one of the stories, The Pinking Shears, the character is a spirited little girl called Jean Louie who gives a friend a haircut and faces the wrath of the child's father. Perhaps a hint of the forthright Scout to come?

In another, The Binoculars, a child starting school is berated by the teacher for already knowing how to read. A version of that story appears early on in Mockingbird. Ed, who's a retired English professor, calls them apprentice stories which aren't the fullest expression of her genius and yet there's genius in them. She was a brilliant writer in the making and you see something of her brilliance in these stories.

The publication of Go Set A Watchman sparked controversy. Atticus Finch, the anti-racist hero of To Kill A Mockingbird, is portrayed as a racist. There were questions about whether Lee, who had significant health issues by then, had the capacity to give full consent. I ask whether it's an invasion of Lee's privacy to publish posthumously these stories that Lee didn't choose to make public in her lifetime. Ed Lee Conner is clear that, when it comes to The Land of Sweet Forever, that's an easy judgment to make, she attempted to publish all these stories.

The Land of Sweet Forever is set to be released on October 21, 2025, promising to revive interest in Harper Lee's captivating early works.