Geri Halliwell-Horner "did fencing lessons" for her young adult novel series

She told The Sun newspaper's Bizarre column: "I actually did fencing lessons because there are two scenes in it where she is fencing, and I thought, 'I've got no idea how to carry this.'

"I got this man to teach me because I thought, 'How can I describe that authentically if I don't know how to do it?'"

The New York Times bestselling author's latest book is a follow-up to her 2023 novel 'Rosie Frost and the Falcon Queen', and it sees the character fight to know the truth about her past and her "family's ancient ties to Bloodstone [Island]" amid "mutant animals are on the loose, jealous classmates [wanting] to bring Rosie down" and dealing with "a black hole".

And the Spice Girls icon has admitted that writing the book was "probably the hardest thing [she] has ever done".

She told the US TV show 'Extra': "It is probably the hardest thing I've ever done.

"The mental stamina of completing a novel is massive, like, to remember what you did in that bit.

"It's sort of like, 'Oh, my God.'

"To really show up for it is massive, but then when you see the cover and response, then there's something really thrilling about it and you think, 'Wow... then she's worth it.'"

The 'Mi Chico Latino' hitmaker wanted to enter the literary world because she "really [wanted] to see a new female character that really connects with us".

She told Billboard: "I love books. I just love them. They've been my best friends, my companions.

"I always love to find myself in a story and process something.

"And I just thought, 'You know what? I really want to see a new female character that really connects with us, with who we are now, and someone that is not perfect, and finding the courage you never knew you had.'"