Watch: A battered Harry Potter paperback has been valued at £1,500
But expert Justin Croft revealed the poor condition of the book did not affect its value as it has been signed by Harry Potter creator Rowling with the message: "To Helen - This is the condition I like to see my books in! (Read)."
She also had a First Edition hardback copy of Harry Potter and the Chamber of Secrets.
Croft told her: "These are possibly the worst condition I've seen on the Roadshow."
But he added: "I think I would say £1,000 to £1,500 on this which is really just for the inscription."
Pointing to the second, he added: "And this, being a first edition albeit without the dust jacket, £3,000 to £3,500."
Helen revealed: "Growing up, Harry Potter meant an awful lot to me and my family.
"The Harry Potter paperback I have there I was given in my stocking one year for Christmas and when I started reading it I couldn't put it down.
"When the second book came out JK Rowling came to the Edinburgh book festival and she did a signing afterwards. She signed it for me."
In June 2020 Rowling was 'cancelled' over her views on trans issues, and became the subject of abuse and even death threats from activists who disagree with her stance on protecting sex-based rights for women.
The author responded to a story with a headline that read: “Opinion: Creating a more equal post-COVID-19 world for people who menstruate.”
She tweeted: “‘People who menstruate’. I’m sure there used to be a word for those people. Someone help me out. Wumben? Wimpund? Woomud?”
The writer went on to publish an essay online in which she claimed - as a domestic violence survivor - that she felt allowing trans people to use single-sex bathrooms and changing rooms could be "offering cover to predators".
Harry Potter star Daniel Radcliffe apologised to Harry Potter fans for Rowling’s comments.
Emma Watson, who starred as Hermione Granger in the franchise, said: "Trans people are who they say they are and deserve to live their lives without being constantly questioned or told they aren't who they say they are.
"I want my trans followers to know that I and so many other people around the world see you, respect you and love you for who you are."