Harry Potter author JK Rowling has said it is "painful" to know that her mother never knew about her writing success.
Rowling said she was beset with "guilt and worry and anxiety" when her mother Anne was diagnosed with multiple sclerosis, a disease which led to her death in 1990.
Speaking on Radio 4's Woman's House, she said she regretted her mother not being around to see the books become bestsellers.
"She never knew about Harry Potter - I started writing it six months before she died, so that is painful. I wish she'd known."
Harry Potter creator JK Rowling is turning sports writer to pen a series of match reports from the fictional Quidditch World Cup.
The writer's fans will be able to read regular updates from the tournament, which first featured in her books about the teenage wizard, on the Pottermore website.
Quidditch - a fictional sport played by the student wizards on flying broomsticks in the best-selling books - is so popular with fans that they have adapted a version of the game that can really be played. Characters from the books are expected to feature in the reports.
JK Rowling will publish her second crime novel this summer.
'The Silkworm' sees private detective Cormoran Strike hunting the murderer of a novelist.
It is due to be published on June 19.
JK Rowling has admitted what many Harry Potter fans have long suspected - lead characters Harry Potter and Hermione Granger should have ended up together.
Granting a rare interview to Wonderland magazine, the author spoke candidly to Emma Watson, the actress who played Hermione, who was also guest editing the publication.
In an extract from this week's issue, printed in The Sunday Times (£), the author said:
"I wrote the Hermione/Ron relationship as a form of wish fulfilment. That’s how it was conceived, really. For reasons that have very little to do with literature and far more to do with me clinging to the plot as I first imagined it, Hermione ended up with Ron.”
She went on: "I know, I’m sorry, I can hear the rage and fury it might cause some fans, but if I’m absolutely honest, distance has given me perspective on that. It was a choice I made for very personal reasons, not for reasons of credibility."
Rowling even suggested that Hermione and Ron Weasley would have ended up in relationship counselling.
“Am I breaking people’s hearts by saying this? I hope not,” Rowling added.
JK Rowling has announced Harry Potter will return - but this time it will be on the stage.
The author said she is working on a stage play that explores the boy wizard's early years under the Dursleys' staircase.
Although she will not script the play herself, Rowling will co-produce the project with theatre producers Sonia Friedman and Colin Callender.
Rowling said: "Over the years I have received countless approaches about turning Harry Potter into a theatrical production.
"But Sonia and Colin's vision was the only one that really made sense to me, and which had the sensitivity, intensity and intimacy I thought appropriate for bringing Harry's story to the stage."
Author J K Rowling has said that she is more proud of her time as a single mother than any other part of her life and called on politicians to do more to support struggling single parents to get back in to work.
Writing for Gingerbread, a charity which supports single parents that she is a patron of, she said finds: "the language of ‘skivers versus strivers’ particularly offensive when it comes to single parents."
Rowling wrote: "I would say to any single parent currently feeling the weight of stereotype or stigmatization that I am prouder of my years as a single mother than of any other part of my life.
"Yes, I got off benefits and wrote the first four Harry Potter books as a single mother, but nothing makes me prouder than what Jessica told me recently about the first five years of her life: ‘I never knew we were poor. I just remember being happy.’"
Rowling became a single parent on benefits after her marriage ended after the birth of her first daughter Jessica and she struggled to find work after returning to the UK from Portugal.
JK Rowling is to make her screenwriting debut for a Harry Potter spin-off film based on a minor character in the series.
Fantastic Beasts and Where to Find Them will feature fictitious author Newt Scamander, writer of the Hogwarts textbook of the same name.
Rowling made the decision when she was asked by Warner Bros for permission to create the film.
She said: "As I considered Warners' proposal, an idea took shape that I couldn't dislodge. That is how I ended up pitching my own idea for a film to Warner Bros."
It's not the only project the author has taken on since completing the Potter series - Rowling has since released two novels.
JK Rowling has announced she will donate all global net royalties due to her from sales of The Cuckoo's Calling to The Soldiers' Charity over the next three years.
The donations will date from July 14, the day that her pseudonym Robert Galbraith's true identity was made known.
This donation is being made to The Soldiers' Charity partly as a thank you to the Army people who helped me with research, but also because writing a hero who is a veteran has given me an even greater appreciation and understanding of exactly how much this charity does for ex-servicemen and their families, and how much that support is needed.
I always intended to give The Soldiers' Charity a donation out of Robert's royalties but I had not anticipated him making the bestseller list a mere three months after publication - indeed, I had not counted on him ever being there!
The charity thanked her for the "tremendous show of support" and said the donations would make a "huge difference to the lives of thousands of soldiers, former soldiers and their families who are in real need".
Legal firm Russells was found to be responsible for the leak that led to the Sunday Times revealing her as Robert Galbraith, the writer of the crime novel The Cuckoo's Calling.
The firm apologised "unreservedly" in a statement earlier this month, admitting that one of its partners, Chris Gossage, had told his wife's best friend, Judith Callegari, that Galbraith was in fact JK Rowling during a "private conversation".
The author brought proceedings in London's High Court against Mr Gossage and Mrs Callegari, who had gone on to reveal her secret identity during a Twitter exchange with a journalist.
JK Rowling has received a substantial payout at London's High Court from a law firm which breached her confidentiality by revealing she was writing under a pseudonym.
The Harry Potter author has donated the money to charity.